Criminal gangs are tricking East Europeans into sham Scottish marriages with Asian men – selling the women for sex, labor and passports – in an expose that campaigners say reveals the extent of human slavery worldwide.

The cross-border story of how destitute women are lured from Romania and Slovakia with the promise of work in Western Europe, then sold in Scotland as slaves is told in a BBC television documentary to be aired on Wednesday.

Anti-slavery activists said the story was no surprise, with an estimated 46 million people living in some form of modern slavery around the globe.

“Sadly, the issue of sham marriage and sexual exploitation of vulnerable women and girls is not a new phenomenon,” said Justine Currell, Executive Director at Unseen, an anti-slavery group.

“This story highlights the depths that these gangs will go to make a profit, regardless of the terrible consequences for the individual,” she told the Thomson Reuters Foundation.

“We must put a stop to this horrendous practice by locking up those responsible and protecting those most at risk of exploitation.” media agencies