Ruja Ignatova called herself the Cryptoqueen. She told people she had invented a cryptocurrency to rival Bitcoin, and persuaded them to invest billions. Then, two years ago, she disappeared. Jamie Bartlett spent months investigating how she did it for the Missing Cryptoqueen podcast, and trying to figure out where she's hiding.
In early June 2016 a 36-year-old businesswoman called Dr Ruja Ignatova walked on stage at Wembley Arena in front of thousands of adoring fans. She was dressed, as usual, in an expensive ballgown, wearing long diamond earrings and bright red lipstick.
She told the cheering crowd that OneCoin was on course to become the world's biggest cryptocurrency "for everyone to make payments everywhere".