If you had millions of of ill gotten pounds, dollars or rubles you would need to find a way of hiding where it came from and the very fact that it's yours in the first place. It turns out that the place in the world best suited to provide this service is the UK. Oligarchs from all over the world use British financial services, overseas territories and even tube stations to hide their wealth.
To discuss this, Ash Sarkar meet Oliver Bullough, author of "Butler to the World: The book the oligarchs don’t want you to read - how Britain became the servant of tycoons, tax dodgers, kleptocrats and criminals"