Trying to find a sci-fi movie

Im trying to find a movie that's been bugging me for years. I saw a movie on the sci fi chanel years ago(mid 2000s to late), it was one of those very late night movies... it was about a man who had some sort of parasite or creature in him, he seemed to be like a detective of some sort. He and his partner seemed to be looking for some sort of information (maybe on how to get rid of the creature). There is a scene where he is interrogating a man and the creature comes out of the palm of his hand. In the end i think they try and rid him of the creature but it is apparent that the creature now lives in his partner. If anyone can help me it'd be great, it's an itch i get and can never find anything on it ever.