In recent years, people around the world have lost hundreds of millions of dollars to online romance scams.
One of the most lucrative of these, being run by criminal gangs throughout Southeast Asia, is called the “Pig Butcher Romance Scam”.
The scammers refer to their victims as pigs, whom they set out to “butcher” — or swindle — out of as much money as possible.
A BBC World Service investigation has spoken to former insiders, who reveal the brutal conditions of many who worked as scammers and the sophisticated techniques used.
Watch the full documentary on BBC iPlayer, and read our previous coverage on the issue here.