Are they indigenous to the UK then now?!
Yes. They are very popular as pets since a change in U.K law in 2007 and a number have escaped. I don't think these are the Racoons we are most familiar with though, the North American variety but European Racoons found in mainland Europe. I once saw a Racoon, American variety half a mile from where I live in The mid 80's crossing a lane at about one in the morning. I later learned that it had escaped from Chester Zoo , 10 miles away.
EDIT, Got my facts mixed up there, in fact they are Asiatic Racoons also known as Racoon Dogs and there's an epidemic of them in Germany from the deliberate release of a pair many years ago
Pete
Either way not indigenous to the UK imo. Few escaped pets and Zoo animals doesn't make them a naturally occurring species or native species to the UK.