2. The Bitcoin Killer

Not all is as it seems with Dr Ruja's revolutionary cryptocurrency, OneCoin.

The Missing Cryptoqueen is an eight-part series for BBC Sounds, with new episodes every Thursday.

Presenter: Jamie Bartlett Producer: Georgia Catt Story consultant: Chris Berube Editor: Philip Sellars Original music and sound design: Phil Channell Original music and vocals: Dessislava Stefanova and the London Bulgarian Choir