On a secretly recorded tape, a confident-sounding man boasts of his influence with corrupt police. He sounds like a crime boss, or some kind of underworld Mr Big. He says he can help make problems with the law go away. But first, he wants the truth about a murder.

But who is Mr Big? Alicia Bridges investigates.

Mr Big is the latest season of Unravel, the ABC's award-winning true crime podcast.