The actor said quitting his role as dectective Ronnie Brooks was "one of the hardest decisions I have ever had to make" and refused to rule out a return to the show.He added: "Ronnie Brooks is one of my best friends.""It's been an absolute pleasure to inhabit Ronnie's mac for as long as I have. Eight series is a wonderful achievement for everyone involved in the production."I hope one day to revisit him, but for now I'd like the opportunity to pursue other drama projects which ITV are developing."The final episode of Law and Order: UK will air on UTV next Wednesday at 9pm, but ITV bosses said it could make a comeback.Director of drama commissioning, Steve November, said: "There may well come a time when we re-visit Law And Order: UK."For the moment, we'll be resting the series whilst we continue to refresh our drama slate."The show, based on a popular US drama, was first shown in the UK in 2009.