Police in Romania and Hungary say they have broken up a human trafficking ring that convinced vulnerable people, many fresh off welfare, to work in slave-like conditions in Budapest.

For more than a decade, traffickers brought men and women from Romania to the Hungarian capital, promising them relatively high wages and good housing.

Instead, they were put to work for low wages, mainly at a waste recycling plant near Budapest, according to details of the investigation released Friday.

Five men and three women were detained as part of the investigation, and most of them come from the same family originally from central Romania, the police say.

More than 30 victims have been identified. They lived 25 to a room in unsanitary conditions and were required to work at least 12 hours a day, seven days a week, for a pittance.

“The perpetrators’ preferred victims were those from foster care centers, who were easy to convince and exploited through false promises,” according to Romanian prosecutors, specialized in combating organized crime.

“Victims were forced, including through acts of violence, to perform physically and psychologically unbearable work … and to live in inhumane conditions under constant surveillance.”

They were forced to work, often outside in the cold, without proper work clothes or protective equipment, and were denied adequate food and medical care. Their documents were taken to stop them fleeing, authorities added.

Six of those arrested are from the same family from the town of Sfantu Gheorghe in Romania’s Szeklerland, which is home to a large Hungarian community.

Seventy Hungarian police officers took part in dawn raids on Tuesday, seizing documents, vehicles, €100,000 (£83,000) in cash and gold jewelery used by the gang.

In Romania, three houses were searched by the police in the villages of Ozun and Chilieni.