--- Backend.php.orig	2016-09-13 12:04:27.000000000 +0200
+++ Backend.php	2016-10-02 18:43:20.356427300 +0200
@@ -1102,6 +1102,9 @@
                     $this->removeEntity($propertyValue);
                 }
             }
+	    if ($columnMap && ($columnMap->getTypeOfRelation() === \TYPO3\CMS\Extbase\Persistence\Generic\Mapper\ColumnMap::RELATION_HAS_AND_BELONGS_TO_MANY)) {
+		$this->deleteAllRelationsFromRelationtable($object, $propertyName);
+	    }
         }
     }