Police across Europe prepare for a top-secret operation: the hacking of EncroChat, an encrypted phone network favoured by organised crime groups.

EncroChat’s server has been discovered in northern France. The French police are planning to secretly inject some code into the users’ next software update. If it works, police could be reading the criminals’ messages for weeks.

At the Metropolitan Police in London, DCI Driss Hayoukane is summoned to a confidential meeting where he hears about the plan. He realises this is a once in a lifetime opportunity and decides to put his retirement on hold.

Presenter: Mobeen Azhar Series Producer: Andrew Hosken Editor and Executive Producer: Innes Bowen Catching the Kingpins is a BBC Studios Production for BBC Sounds.