diff --git a/src/main/java/org/alfresco/rest/api/impl/GroupsImpl.java b/src/main/java/org/alfresco/rest/api/impl/GroupsImpl.java
index 22e824404e..0a875fae18 100644
--- a/src/main/java/org/alfresco/rest/api/impl/GroupsImpl.java
+++ b/src/main/java/org/alfresco/rest/api/impl/GroupsImpl.java
@@ -58,6 +58,7 @@ import org.alfresco.rest.api.model.GroupMember;
 import org.alfresco.rest.framework.core.exceptions.ConstraintViolatedException;
 import org.alfresco.rest.framework.core.exceptions.EntityNotFoundException;
 import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
+import org.alfresco.rest.framework.core.exceptions.NotFoundException;
 import org.alfresco.rest.framework.core.exceptions.PermissionDeniedException;
 import org.alfresco.rest.framework.core.exceptions.UnsupportedResourceOperationException;
 import org.alfresco.rest.framework.resource.parameters.CollectionWithPagingInfo;
@@ -809,7 +810,15 @@ public class GroupsImpl implements Groups
         }
 
         validateGroupMemberId(groupMemberId);
-        // TODO: Verify if groupMemberId is member of groupId
+
+        // Verify if groupMemberId is member of groupId
+        AuthorityType authorityType = AuthorityType.getAuthorityType(groupMemberId);
+        Set<String> parents = authorityService.getContainingAuthorities(AuthorityType.GROUP, groupMemberId, true);
+        if (!parents.contains(groupId))
+        {
+            throw new NotFoundException(groupMemberId + " is not member of " + groupId);
+        }
+
         authorityService.removeAuthority(groupId, groupMemberId);
     }
 
diff --git a/src/test/java/org/alfresco/rest/api/tests/GroupsTest.java b/src/test/java/org/alfresco/rest/api/tests/GroupsTest.java
index 117027fa63..cd797b77d1 100644
--- a/src/test/java/org/alfresco/rest/api/tests/GroupsTest.java
+++ b/src/test/java/org/alfresco/rest/api/tests/GroupsTest.java
@@ -1780,6 +1780,11 @@ public class GroupsTest extends AbstractSingleNetworkSiteTest
                 groupsProxy.deleteGroupMembership(GROUP_EVERYONE, groupMemberA.getId(), HttpServletResponse.SC_CONFLICT);
             }
 
+            // Removing a group that is not a member (REPO-1943)
+            {
+                groupsProxy.deleteGroupMembership(groupB.getId(), personMember.getId(), HttpServletResponse.SC_NOT_FOUND);
+            }
+
             // Authentication failed
             {
                 setRequestContext(networkOne.getId(), GUID.generate(), "password");
@@ -1788,8 +1793,10 @@ public class GroupsTest extends AbstractSingleNetworkSiteTest
 
             // User does not have permission to delete a group membership
             {
+                setRequestContext(networkOne.getId(), networkAdmin, DEFAULT_ADMIN_PWD);
+                groupsProxy.createGroupMember(groupA.getId(), personMember, HttpServletResponse.SC_CREATED);
                 setRequestContext(user1);
-                groupsProxy.deleteGroupMembership(groupA.getId(), groupMemberA.getId(), HttpServletResponse.SC_FORBIDDEN);
+                groupsProxy.deleteGroupMembership(groupA.getId(), personMember.getId(), HttpServletResponse.SC_FORBIDDEN);
             }
         }
         finally