I dont know if the OP intended this thread to be just highlighting the dangerous world we live in or if he was trying to tell us he'd punted with this girl in the past.
Either way, unless you have any information I'd stay away. If they knock on your door then that's another thing, tell them what you know. If you get the "good cop - bad cop" treatment the way to collapse their method is to be a bastard to both of them. Yes, the really nice cop who's bringing you tea, complimenting you, making you feel relaxed - be a right bastard to him. Because he's just running a routine.