I think Sky One in the UK might have shown this back in the day, but it was an undercover crime drama series created by Frank Lupo and Stephen J. Cannell (The A-Team) and starred Ken Wahl as Vinnie Terranova, an FBI agent with mob connections who used these to infiltrate various criminal organizations to get the goods on their activities. It wasn't a surefire ratings success in the US but always got good reviews.
"What was I thinking of, hitting him? Nothing. No, I know. I hate him! I hate his guts, I hate everything he stands for with his PACE and his plus and his statements of purpose and his smiling at the punters and his have a nice day! I mean when was the last time he ever nicked anybody, eh? A real villain! When was the last time he ever put himself on the line?"