Delete attachment linked to activity in ICWEB

Hello

I have implemented the deltion of attachment using following code. the commands went sucessfull but it is not deleting attachment(which is linked to activity/interaction record)

lr_entity_col = lv_bo->get_related_entities( iv_relation_name = cl_crm_cm_genil_comp=>gc_rel_bo_document_ref ).

lv_bo = lr_entity_col->get_first( ).

lv_bo->delete( ).

lv_core->modify( ).

lv_transaction = lv_core->get_transaction( ).

lv_transaction->save( ).

lv_transaction->commit( ).

Does anybody implemented similar logic?

Regards,

Laxman