Crypto-currency and cybercrime have together provided the DPRK with the hard currency it needed to continue with its nuclear weapons programme.

Ed Butler speaks to sanctions specialist Nigel Kushner of W Legal about how Bitcoin and the like are used by sanctioned individuals to continue doing business outside the official banking system. In North Korea's case, much of the business involves outright theft - be it the Wannacry ransomware attack, the hacking of the Bangladeshi central bank's accounts, or robbing of various crypto-exchanges in recent years.

Priscilla Moriuchi of the internet security firm ‎Recorded Future explains how North Korea built this surprisingly sophisticated cybercrime business, while Jesse Spiro of blockchain analysis firm Chainalysis describes the money laundering schemes the country has employed.

Producer: Joshua Thorpe

(Picture: North Korea flag button on computer keyboard; Credit: alexsl/Getty Images)