Tried to open the rear door on my Audi this morning. It eventually opened but refused to latch when closed.

The door lock lever dosn't seem to offer any resistance like the opposite side. The lever mechanism inside the lock does not click in the locked position so there is no grab on male peg on the door frame.

So its impossible to shut the door . Realise now that I washed the car yesterday and there was a heavy frost overnight. So suspect I have broken a part

Any ides what parts are brokenand how I can go about fixing it

Many thanks