Hi Siany

Thanks for the info, I've contacted a number of people about this. The RSPCA said that leaving a cat behind without care arrangements is a prosecutable offense and also said I had a good case if there was a dispute etc.
Petlog (the company that the chip is registered to) said they wouldn't be a problem unless the cat is tagged as missing on there data base, they would change the details after getting confirmation of the cats history from the vet etc. Petlog also were keen to state that a chip isn't proof of ownership (sounds odd I know).
Considering the owners neglected him went abroad I very much doubt they even care about the chip info etc, so I think I'll go ahead and get it changed, if they do come out of the wood work I have plenty of proof of neglect and besides they would have to get solicitors involved as Petlog aren't legally allowed to pass on my details without consent, which would be very surprising considering they just left him and haven't made any efforts to contact their previous address to inquire about the cat.

Its all rather silly, thanks again for the information. In your experience would you just leave it be and not change the chip info?

Cheers, BrookyPet