Citroen Saxo rear door locked and won't open

Would force off the inside panel,without breaking it of course,to gain access to mechanism,probably something,s popped off or latch faulty.

Thanks, but we have the removed the panel and even tried to take off the exterior door handle, but not sure how to remove the casing from the inside. There is very restricted space and also not sure how it is clipped on.

Try lifting the unlock button and moving the interior dr handle while someone pulls on the dr from the outside.

I think the rear outside door handles may be rivetted and need drilling to remove .May be plastic clip holding linkage to inside lock assembly .