The Bill - Season 16 Episode 52 Doppelganger

Boyden is shocked to discover that someone has been impersonating him, raiding illegal poker games and pocketing all the cash, and decides to go undercover as a punter to trap him. However, during the operation, the technology provided by the yard goes haywire and all of the suspects manage to escape without capture. Meanwhile, as the phony Boyden attacks and robs a prostitute, the real Boyden finds two Yardies on his case set out for revenge. As a second operation is organised, Boyden asks one of the players from the first game to go undercover and catch the fake police officers in the act. However, having gotten the Yardies on his side, Boyden organises sinister revenge for his fake counterpart.