diff --git a/lib/content-services/src/lib/legal-hold/services/legal-hold.service.ts b/lib/content-services/src/lib/legal-hold/services/legal-hold.service.ts
index 06c6832c31..906d9ff6f6 100644
--- a/lib/content-services/src/lib/legal-hold/services/legal-hold.service.ts
+++ b/lib/content-services/src/lib/legal-hold/services/legal-hold.service.ts
@@ -51,4 +51,43 @@ export class LegalHoldService {
             catchError((err) => throwError(err))
         );
     }
+
+
+    /**
+     * Add a child of a hold with id holdId.
+     *
+     * @param ids The list of manage hold Ids
+     * @param holdId The Id of the hold to witch children will be added
+     * @returns List of assigned holds Hold[]
+     */
+    addHoldsToExistingHold(ids: string[], holdId: string): Observable<Hold[]> {
+        return from(this.legalHoldApi.saveToExistingHolds(ids, holdId)).pipe(
+            map(({ list }) =>
+                list?.entries?.map(({ entry }) => ({
+                    id: entry?.id,
+                    name: entry?.name,
+                }))
+            ),
+            catchError((err) => throwError(err))
+        );
+    }
+
+    /**
+     * Deletes the relationship between a child with id holdChildId and a parent hold with id holdId.
+     *
+     * @param holdId The handled hold Id
+     * @param holdChildId The Id of the child hold which is removed
+     * @returns List of assigned holds Hold[]
+     */
+    deleteHoldFromExistingHold(holdId: string, holdChildId: string): Observable<Hold[]> {
+        return from(this.legalHoldApi.deleteFromExistingHolds(holdId, holdChildId)).pipe(
+            map(({ list }) =>
+                list?.entries?.map(({ entry }) => ({
+                    id: entry?.id,
+                    name: entry?.name,
+                }))
+            ),
+            catchError((err) => throwError(err))
+        );
+    }
 }
diff --git a/lib/content-services/src/lib/legal-hold/services/legal-holds.service.spec.ts b/lib/content-services/src/lib/legal-hold/services/legal-holds.service.spec.ts
index 8b2f6a4e15..9188d45214 100644
--- a/lib/content-services/src/lib/legal-hold/services/legal-holds.service.spec.ts
+++ b/lib/content-services/src/lib/legal-hold/services/legal-holds.service.spec.ts
@@ -71,4 +71,30 @@ describe('LegalHoldsService', () => {
             });
         });
     });
+
+    describe('addHoldsToExistingHold', () => {
+        it('should add holds to existing hold', (done) => {
+            const childrenIds = ['abc', 'qwe'];
+            spyOn(service.legalHoldApi, 'saveToExistingHolds').and.returnValue(Promise.resolve(legalHolds));
+
+            service.addHoldsToExistingHold(childrenIds, mockId).subscribe((holds) => {
+                expect(holds).toEqual(returnedHolds);
+                expect(service.legalHoldApi.saveToExistingHolds).toHaveBeenCalledWith(mockId, childrenIds);
+                done();
+            });
+        });
+    });
+
+    describe('deleteHoldFromExistingHold', () => {
+        it('should delete hold from existing hold', (done) => {
+            const childrenId = 'qwe';
+            spyOn(service.legalHoldApi, 'deleteFromExistingHolds').and.returnValue(Promise.resolve(legalHolds));
+
+            service.deleteHoldFromExistingHold(mockId, childrenId).subscribe((holds) => {
+                expect(holds).toEqual(returnedHolds);
+                expect(service.legalHoldApi.deleteFromExistingHolds).toHaveBeenCalledWith(mockId, childrenId);
+                done();
+            });
+        });
+    });
 });
diff --git a/lib/js-api/src/api/gs-core-rest-api/api/legal-hold.api.ts b/lib/js-api/src/api/gs-core-rest-api/api/legal-hold.api.ts
index 7b92c91b54..322fef92f7 100644
--- a/lib/js-api/src/api/gs-core-rest-api/api/legal-hold.api.ts
+++ b/lib/js-api/src/api/gs-core-rest-api/api/legal-hold.api.ts
@@ -52,4 +52,40 @@ export class LegalHoldApi extends BaseApi {
             returnType: HoldPaging
         });
     }
+
+    /**
+     * Adds to existing hold
+     *
+     * @param holdId The identifier of a hold.
+     * @param ids list of ids of holds to add to existing hold
+     * @returns Promise<NodeChildAssociationPaging>
+     */
+    saveToExistingHolds(ids: string[], holdId: string): Promise<HoldPaging> {
+        throwIfNotDefined(holdId, 'holdId');
+
+        return this.post({
+            path: `/holds/{holdId}/children`,
+            pathParams: { holdId },
+            bodyParam: ids,
+            returnType: HoldPaging
+        });
+    }
+
+    /**
+     * Deletes the relationship between a child with id holdChildId and a parent hold with id holdId.
+     *
+     * @param holdId The handled hold Id
+     * @param holdChildId The Id of the child hold which is removed
+     * @returns List of assigned holds Hold[]
+     */
+    deleteFromExistingHolds(holdId: string, holdChildId: string): Promise<HoldPaging> {
+        throwIfNotDefined(holdId, 'holdId');
+        throwIfNotDefined(holdChildId, 'holdChildId');
+
+        return this.delete({
+            path: `/holds/{holdId}/children/{holdChildId}`,
+            pathParams: { holdId, holdChildId },
+            returnType: HoldPaging
+        });
+    }
 }