diff --git a/app/lib/admin/actions/actions.dart b/app/lib/admin/actions/actions.dart
index 6805823b1c..827901b4f7 100644
--- a/app/lib/admin/actions/actions.dart
+++ b/app/lib/admin/actions/actions.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:pub_dev/admin/actions/create_publisher.dart';
+import 'package:pub_dev/admin/actions/merge_moderated_package_into_existing.dart';
 import 'package:pub_dev/admin/actions/publisher_block.dart';
 import 'package:pub_dev/admin/actions/publisher_members_list.dart';
 import 'package:pub_dev/admin/actions/remove_package_from_publisher.dart';
@@ -65,6 +66,7 @@ final class AdminAction {
 
   static List<AdminAction> actions = [
     createPublisher,
+    mergeModeratedPackageIntoExisting,
     publisherBlock,
     publisherMembersList,
     removePackageFromPublisher,
diff --git a/app/lib/admin/actions/merge_moderated_package_into_existing.dart b/app/lib/admin/actions/merge_moderated_package_into_existing.dart
new file mode 100644
index 0000000000..c5f02a252d
--- /dev/null
+++ b/app/lib/admin/actions/merge_moderated_package_into_existing.dart
@@ -0,0 +1,71 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:pub_dev/admin/actions/actions.dart';
+import 'package:pub_dev/package/backend.dart';
+import 'package:pub_dev/package/models.dart';
+import 'package:pub_dev/shared/datastore.dart';
+
+final mergeModeratedPackageIntoExisting = AdminAction(
+  name: 'merge-moderated-package-into-existing',
+  summary:
+      'Removes a ModeratedPackage tombstone and merges it into an existing Package entity.',
+  description: '''
+This action will remove a package moderation tombstone (ModeratedPackage)
+entity from the Datastore, and merges its deleted version list into its
+already existing Package entity.
+The removal will unblock new uploads to the package.
+
+WARNING: Ownership information stored on the ModeratedPackage (e.g. publisher
+         or uploaders) will be lost.
+
+NOTE: The published versions will be rolled into Package.deletedVersions.
+
+Fails if that package has no ModeratedPackage tombstone.
+Fails if that package has no existing Package entity.
+''',
+  options: {
+    'package':
+        'The name of ModeratedPackage to merge into its existing Package.',
+  },
+  invoke: (args) async {
+    final packageName = args['package'] as String;
+
+    await withRetryTransaction(dbService, (tx) async {
+      // check ModeratedPackage existence
+      final mpKey =
+          dbService.emptyKey.append(ModeratedPackage, id: packageName);
+      final mp = await tx.lookupOrNull<ModeratedPackage>(mpKey);
+      InvalidInputException.check(
+          mp != null, 'ModeratedPackage does not exists.');
+
+      // check Package existence
+      final pKey = dbService.emptyKey.append(Package, id: packageName);
+      final p = await tx.lookupOrNull<Package>(pKey);
+      InvalidInputException.check(p != null, 'Package does not exists.');
+
+      // update deleted version list
+      final versionList = await tx.query<PackageVersion>(pKey).run().toList();
+      final existingVersions = versionList.map((v) => v.version!).toSet();
+      final deletedVersions = (mp!.versions ?? <String>[])
+          .where((v) => !existingVersions.contains(v))
+          .toList();
+      if (deletedVersions.isNotEmpty) {
+        p!.deletedVersions = <String>{
+          ...?p.deletedVersions,
+          ...deletedVersions,
+        }.toList();
+      }
+
+      tx.insert(p!);
+      tx.delete(mpKey);
+    });
+    await purgePackageCache(packageName);
+
+    return {
+      'package': packageName,
+      'merged': true,
+    };
+  },
+);
diff --git a/app/test/admin/api_actions_test.dart b/app/test/admin/api_actions_test.dart
index beb5880c11..24671dd497 100644
--- a/app/test/admin/api_actions_test.dart
+++ b/app/test/admin/api_actions_test.dart
@@ -5,11 +5,16 @@
 import 'dart:convert';
 
 import 'package:_pub_shared/data/admin_api.dart';
+import 'package:clock/clock.dart';
 import 'package:pub_dev/account/backend.dart';
 import 'package:pub_dev/package/backend.dart';
+import 'package:pub_dev/package/models.dart';
 import 'package:pub_dev/publisher/backend.dart';
+import 'package:pub_dev/shared/datastore.dart';
 import 'package:test/test.dart';
 
+import '../package/backend_test_utils.dart';
+import '../shared/handlers_test_utils.dart';
 import '../shared/test_models.dart';
 import '../shared/test_services.dart';
 
@@ -107,4 +112,51 @@ void main() {
     final emails = await accountBackend.getEmailsOfUserIds(neon.uploaders!);
     expect(emails, {'admin@pub.dev'});
   });
+
+  testWithProfile('merge existing moderated package into existing',
+      fn: () async {
+    final originalVersionList = await packageBackend.listVersions('oxygen');
+
+    // inject "bad" ModeratedPackage tombstone
+    await dbService.commit(inserts: [
+      ModeratedPackage()
+        ..parentKey = dbService.emptyKey
+        ..id = 'oxygen'
+        ..name = 'oxygen'
+        ..moderated = clock.now().toUtc()
+        ..versions = [
+          originalVersionList.versions.first.version, // existing
+          '8.99.100', // non-existing
+        ]
+        ..uploaders = [],
+    ]);
+
+    // verify that new upload is blocked
+    final pubspecContent = generatePubspecYaml('oxygen', '9.0.0');
+    final bytes = await packageArchiveBytes(pubspecContent: pubspecContent);
+    final rs1 = createPubApiClient(authToken: adminClientToken)
+        .uploadPackageBytes(bytes);
+    await expectApiException(
+      rs1,
+      status: 400,
+      code: 'PackageRejected',
+      message: 'Package name oxygen is reserved',
+    );
+
+    // merge tombstone
+    final api = createPubApiClient(authToken: siteAdminToken);
+    final result = await api.adminInvokeAction(
+      'merge-moderated-package-into-existing',
+      AdminInvokeActionArguments(arguments: {'package': 'oxygen'}),
+    );
+    expect(result.output, {
+      'package': 'oxygen',
+      'merged': true,
+    });
+
+    // verify that upload is unblocked
+    final rs2 = await createPubApiClient(authToken: adminClientToken)
+        .uploadPackageBytes(bytes);
+    expect(rs2.success.message, contains('Successfully uploaded'));
+  });
 }