Dr Ruja Ignatova is the founder of the cryptocurrency One Coin that promised to change money forever. Within two years of launching the company she claimed to have 3.5 million members and hundreds of thousands of investors, with offices all round the world holding events and seminars in major cities. She even packed out Wembley Arena. But in 2017 Dr Ruja got a plane to Athens and hasn't been seen since. Georgia Catt, a BBC producer, and technology writer Jamie Bartlett have been on the search for Dr Ruja for the last year and have just started a podcast series about their investigation for BBC Sounds. They came into the Beyond Today studio to tell us all about her.

Presented by Tina Daheley