Hotpoint Mistral Leeking water?

I have a Hotpoint fridge freezer which is intermittently creating a small puddle of water at the front right hand side. It has been moved on a couple of occasions recently. Owing to a new kitchen being put in.

The bottom part of the freezer has got a small layer (wafer thin) of ice accumulating. I suspect that the seal may be going or air getting into the compartment and causing this. Can anybody offer any suggestions?