diff --git a/modules/nf-core/gatk4/cleansam/environment.yml b/modules/nf-core/gatk4/cleansam/environment.yml
new file mode 100644
index 00000000000..e6f0f713b9a
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/environment.yml
@@ -0,0 +1,6 @@
+channels:
+  - conda-forge
+  - bioconda
+dependencies:
+  # renovate: datasource=conda depName=bioconda/gatk4
+  - "bioconda::gatk4=4.6.2.0"
diff --git a/modules/nf-core/gatk4/cleansam/main.nf b/modules/nf-core/gatk4/cleansam/main.nf
new file mode 100644
index 00000000000..9d447570524
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/main.nf
@@ -0,0 +1,69 @@
+process GATK4_CLEANSAM {
+    tag "${meta.id}"
+    label 'process_medium'
+
+    conda "${moduleDir}/environment.yml"
+    container "${workflow.containerEngine == 'singularity' && !task.ext.singularity_pull_docker_container
+        ? 'https://community-cr-prod.seqera.io/docker/registry/v2/blobs/sha256/ce/ced519873646379e287bc28738bdf88e975edd39a92e7bc6a34bccd37153d9d0/data'
+        : 'community.wave.seqera.io/library/gatk4_gcnvkernel:edb12e4f0bf02cd3'}"
+
+    input:
+    tuple val(meta), path(bam)
+    tuple val(meta2), path(fasta)
+    tuple val(meta3), path(fasta_index)
+    // input file must be sorted for index to be created
+    val create_index
+    val create_md5
+
+    output:
+    tuple val(meta), path("*.bam"), emit: bam
+    tuple val(meta), path("*.bai"), emit: bai, optional: true
+    tuple val(meta), path("*.md5"), emit: md5, optional: true
+    tuple val("${task.process}"), val('gatk'), eval("gatk CleanSam --version | grep GATK | sed 's/.*(GATK) v//'"), topic: versions, emit: versions_gatk
+
+    when:
+    task.ext.when == null || task.ext.when
+
+    script:
+    def args = task.ext.args ?: ''
+    def prefix = task.ext.prefix ?: "${meta.id}"
+    def index = create_index ? "--CREATE_INDEX true" : ""
+    def reference = fasta ? "--REFERENCE_SEQUENCE ${fasta}" : ""
+    def md5 = create_md5 ? "--CREATE_MD5_FILE true" : ""
+    def avail_mem = 3072
+    if (!task.memory) {
+        log.info('[GATK CleanSam] Available memory not known - defaulting to 3GB. Specify process memory requirements to change this.')
+    }
+    else {
+        avail_mem = (task.memory.mega * 0.8).intValue()
+    }
+
+    if ("${bam}" == "${prefix}.bam") {
+        error("Input and output names are the same, use \"task.ext.prefix\" to disambiguate!")
+    }
+
+    """
+    gatk --java-options "-Xmx${avail_mem}M -XX:-UsePerfData"\\
+        CleanSam \\
+        ${args} \\
+        ${reference} \\
+        ${index} \\
+        ${md5} \\
+        --INPUT ${bam} \\
+        --OUTPUT ${prefix}.bam
+
+    """
+
+    stub:
+    def prefix = task.ext.prefix ?: "${meta.id}"
+    def index = create_index ? "touch ${prefix}.bam.bai" : ""
+    def md5 = create_md5 ? "touch ${prefix}.md5" : ""
+    if ("${bam}" == "${prefix}.bam") {
+        error("Input and output names are the same, use \"task.ext.prefix\" to disambiguate!")
+    }
+    """
+    touch ${prefix}.bam \\
+    ${index} \\
+    ${md5}
+    """
+}
diff --git a/modules/nf-core/gatk4/cleansam/meta.yml b/modules/nf-core/gatk4/cleansam/meta.yml
new file mode 100644
index 00000000000..6e63a112db1
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/meta.yml
@@ -0,0 +1,123 @@
+name: "gatk4_cleansam"
+description: Cleans the provided BAM, soft-clipping beyond-end-of-reference
+  alignments and setting MAPQ to 0 for unmapped reads
+keywords:
+  - clean
+  - bam
+  - gatk
+  - sam
+  - clipping
+tools:
+  - "gatk":
+      description: |
+        Developed in the Data Sciences Platform at the Broad Institute, the toolkit offers a wide variety of tools
+        with a primary focus on variant discovery and genotyping. Its powerful processing engine
+        and high-performance computing features make it capable of taking on projects of any size.
+      homepage: https://gatk.broadinstitute.org/hc/en-us
+      documentation: https://gatk.broadinstitute.org/hc/en-us/categories/360002369672s
+      doi: 10.1158/1538-7445.AM2017-3590
+      licence:
+        - "Apache-2.0"
+      identifier: ""
+input:
+  - - meta:
+        type: map
+        description: |
+          Groovy Map containing sample information
+          e.g. [ id:'test', single_end:false ]
+    - bam:
+        type: file
+        description: BAM file
+        pattern: "*.{bam}"
+        ontologies:
+          - edam: "http://edamontology.org/format_2572"
+  - - meta2:
+        type: map
+        description: |
+          Groovy Map containing sample information
+          e.g. [ id:'test', single_end:false ]
+    - fasta:
+        type: file
+        description: Reference FASTA file
+        pattern: "*.{fasta}"
+        ontologies:
+          - edam: "http://edamontology.org/format_1929"
+  - - meta3:
+        type: map
+        description: |
+          Groovy Map containing sample information
+          e.g. [ id:'test', single_end:false ]
+    - fasta_index:
+        type: file
+        description: Index file for the reference FASTA
+        pattern: "*.{fai}"
+        ontologies:
+          - edam: "http://edamontology.org/format_3703"
+  - create_index:
+      type: boolean
+      description: Whether to create an index file for the output BAM
+  - create_md5:
+      type: boolean
+      description: Whether to create an MD5 checksum for the output BAM
+output:
+  bam:
+    - - meta:
+          type: map
+          description: |
+            Groovy Map containing sample information
+            e.g. [ id:'test', single_end:false ]
+      - "*.bam":
+          type: file
+          description: Cleaned BAM file
+          pattern: "*.{bam}"
+          ontologies:
+            - edam: "http://edamontology.org/format_2572"
+  bai:
+    - - meta:
+          type: map
+          description: |
+            Groovy Map containing sample information
+            e.g. [ id:'test', single_end:false ]
+      - "*.bai":
+          type: file
+          description: Index file for the cleaned BAM file
+          pattern: "*.{bai}"
+          ontologies:
+            - edam: "http://edamontology.org/format_3327"
+  md5:
+    - - meta:
+          type: map
+          description: |
+            Groovy Map containing sample information
+            e.g. [ id:'test', single_end:false ]
+      - "*.md5":
+          type: file
+          description: MD5 checksum for the cleaned BAM file
+          pattern: "*.{md5}"
+          ontologies:
+            - edam: "http://edamontology.org/format_3823"
+  versions_gatk:
+    - - ${task.process}:
+          type: string
+          description: The process the versions were collected from
+      - gatk:
+          type: string
+          description: The tool name
+      - "gatk CleanSam --version | grep GATK | sed 's/.*(GATK) v//'":
+          type: eval
+          description: The command used to generate the version of the tool
+topics:
+  versions:
+    - - ${task.process}:
+          type: string
+          description: The process the versions were collected from
+      - gatk:
+          type: string
+          description: The tool name
+      - "gatk CleanSam --version | grep GATK | sed 's/.*(GATK) v//'":
+          type: eval
+          description: The command used to generate the version of the tool
+authors:
+  - "@sofiademmou"
+maintainers:
+  - "@sofiademmou"
diff --git a/modules/nf-core/gatk4/cleansam/tests/main.nf.test b/modules/nf-core/gatk4/cleansam/tests/main.nf.test
new file mode 100644
index 00000000000..e197c256422
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/tests/main.nf.test
@@ -0,0 +1,197 @@
+
+nextflow_process {
+
+    name "Test Process GATK4_CLEANSAM"
+    script "../main.nf"
+    process "GATK4_CLEANSAM"
+    config "./nextflow.config"
+
+    tag "modules"
+    tag "modules_nfcore"
+    tag "gatk4"
+    tag "gatk4/cleansam"
+
+    test("sarscov2 - bam") {
+
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [[], []]
+                input[2] = [[], []]
+                input[3] = false
+                input[4] = false
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(
+                    bam(process.out.bam[0][1]).getReadsMD5(),
+                    process.out.findAll { key, val -> key.startsWith("versions") }
+                ).match()}
+            )
+        }
+    }
+
+    test("sarscov2 - bam + fasta") {
+
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [
+                    [ id:'test', single_end:true ], // meta2 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta', checkIfExists: true)
+                ]
+                input[2] = [
+                    [ id:'test', single_end:true ], // meta3 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta.fai', checkIfExists: true)
+                ]
+                input[3] = false
+                input[4] = false
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(
+                    bam(process.out.bam[0][1]).getReadsMD5(),
+                    process.out.findAll { key, val -> key.startsWith("versions") }
+                ).match()}
+            )
+        }
+    }
+
+        test("sarscov2 - bam + fasta - bai + md5") {
+
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [
+                    [ id:'test', single_end:true ], // meta2 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta', checkIfExists: true)
+                ]
+                input[2] = [
+                    [ id:'test', single_end:true ], // meta3 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta.fai', checkIfExists: true)
+                ]
+                input[3] = true
+                input[4] = true
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(
+                    bam(process.out.bam[0][1]).getReadsMD5(),
+                    file(process.out.bai[0][1]).name,
+                    process.out.md5,
+                    process.out.findAll { key, val -> key.startsWith("versions") }
+                ).match()}
+            )
+        }
+    }
+
+    test("sarscov2 - stub") {
+        options "-stub"
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [[], []]
+                input[2] = [[], []]
+                input[3] = false
+                input[4] = false
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(sanitizeOutput(process.out)).match() }
+            )
+        }
+    }
+    test("sarscov2 - bam + fasta - stub") {
+        options "-stub"
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [
+                    [ id:'test', single_end:true ], // meta2 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta', checkIfExists: true)
+                ]
+                input[2] = [
+                    [ id:'test', single_end:true ], // meta3 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta.fai', checkIfExists: true)
+                ]
+                input[3] = false
+                input[4] = false
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(sanitizeOutput(process.out)).match() }
+            )
+        }
+    }
+
+    test("sarscov2 - bam + fasta - bai + md5 - stub") {
+        options "-stub"
+        when {
+            process {
+                """
+                input[0] = [
+                    [ id:'test', single_end:true ], // meta map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/illumina/bam/test.single_end.sorted.bam', checkIfExists: true)
+                ]
+                input[1] = [
+                    [ id:'test', single_end:true ], // meta2 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta', checkIfExists: true)
+                ]
+                input[2] = [
+                    [ id:'test', single_end:true ], // meta3 map
+                    file(params.modules_testdata_base_path + 'genomics/sarscov2/genome/genome.fasta.fai', checkIfExists: true)
+                ]
+                input[3] = true
+                input[4] = true
+                """
+            }
+        }
+
+        then {
+            assertAll(
+                { assert process.success },
+                { assert snapshot(sanitizeOutput(process.out)).match() }
+            )
+        }
+    }
+}
diff --git a/modules/nf-core/gatk4/cleansam/tests/main.nf.test.snap b/modules/nf-core/gatk4/cleansam/tests/main.nf.test.snap
new file mode 100644
index 00000000000..dd92e91464f
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/tests/main.nf.test.snap
@@ -0,0 +1,180 @@
+{
+    "sarscov2 - bam + fasta - bai + md5 - stub": {
+        "content": [
+            {
+                "bai": [
+                    [
+                        {
+                            "id": "test",
+                            "single_end": true
+                        },
+                        "test.cleaned.bam.bai:md5,d41d8cd98f00b204e9800998ecf8427e"
+                    ]
+                ],
+                "bam": [
+                    [
+                        {
+                            "id": "test",
+                            "single_end": true
+                        },
+                        "test.cleaned.bam:md5,d41d8cd98f00b204e9800998ecf8427e"
+                    ]
+                ],
+                "md5": [
+                    [
+                        {
+                            "id": "test",
+                            "single_end": true
+                        },
+                        "test.cleaned.md5:md5,d41d8cd98f00b204e9800998ecf8427e"
+                    ]
+                ],
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-24T16:44:14.582571234",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    },
+    "sarscov2 - stub": {
+        "content": [
+            {
+                "bai": [
+                    
+                ],
+                "bam": [
+                    [
+                        {
+                            "id": "test",
+                            "single_end": true
+                        },
+                        "test.cleaned.bam:md5,d41d8cd98f00b204e9800998ecf8427e"
+                    ]
+                ],
+                "md5": [
+                    
+                ],
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-23T12:01:12.579259621",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    },
+    "sarscov2 - bam": {
+        "content": [
+            "94fcf617f5b994584c4e8d4044e16b4f",
+            {
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-24T10:35:34.181426878",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    },
+    "sarscov2 - bam + fasta - bai + md5": {
+        "content": [
+            "94fcf617f5b994584c4e8d4044e16b4f",
+            "test.cleaned.bai",
+            [
+                [
+                    {
+                        "id": "test",
+                        "single_end": true
+                    },
+                    "test.cleaned.bam.md5:md5,1cf672787405b01fec776818fb312abc"
+                ]
+            ],
+            {
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-24T10:37:53.473973418",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    },
+    "sarscov2 - bam + fasta": {
+        "content": [
+            "94fcf617f5b994584c4e8d4044e16b4f",
+            {
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-24T10:35:41.370786571",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    },
+    "sarscov2 - bam + fasta - stub": {
+        "content": [
+            {
+                "bai": [
+                    
+                ],
+                "bam": [
+                    [
+                        {
+                            "id": "test",
+                            "single_end": true
+                        },
+                        "test.cleaned.bam:md5,d41d8cd98f00b204e9800998ecf8427e"
+                    ]
+                ],
+                "md5": [
+                    
+                ],
+                "versions_gatk": [
+                    [
+                        "GATK4_CLEANSAM",
+                        "gatk",
+                        "4.6.2.0"
+                    ]
+                ]
+            }
+        ],
+        "timestamp": "2026-04-24T16:44:08.721122709",
+        "meta": {
+            "nf-test": "0.9.5",
+            "nextflow": "26.03.2"
+        }
+    }
+}
\ No newline at end of file
diff --git a/modules/nf-core/gatk4/cleansam/tests/nextflow.config b/modules/nf-core/gatk4/cleansam/tests/nextflow.config
new file mode 100644
index 00000000000..4e288a9c562
--- /dev/null
+++ b/modules/nf-core/gatk4/cleansam/tests/nextflow.config
@@ -0,0 +1,5 @@
+process {
+        withName: 'GATK4_CLEANSAM'{
+            ext.prefix = { "${meta.id}.cleaned"}
+        }
+}