British police freed 24 slaves, including two Russians, in a weekend raid on a traveler’s camp 60 kilometers from central London, news reports said Monday.

More than 200 police officers converged Sunday morning on the Green Acres caravan site in Leighton Buzzard, where they discovered men held in dog kennels, sheds and horse boxes, some too emaciated to eat normally.

"There were up to four men living in tiny and filthy caravans, which were unheated and old. They had no access to running water, no toilet and no washing facilities," said Jo Hobbs, a spokeswoman for Bedfordshire police, the Guardian reported.

The slaves — two Russians, two Romanians, three Poles, and 17 British — were allegedly forced to do grueling work, such as asphalting, from 7 a.m. to 7 p.m. They were between 17 and 50 years old, and at least one of them had been living there for 15 years.

"They were told by the people who had brought them here, 'you have no family now, we are your family.' If they wanted to leave they were threatened," detective chief inspector Sean O’Neil said, the Guardian reported. He added that the men received no received payment or clothes and minimal food, and were beaten if they complained.

Fifteen of the victims are receiving medical treatment, and nine have refused to cooperate with the police, the BBC reported Monday.

Four men and a woman were arrested on suspicion of running the site, which police say might have been the center of a multimillion-dollar slavery network, the Daily Mirror reported.

According to British law, holding a person in servitude is punishable by up to 14 years in prison, while exacting forced labor is punishable by up to seven years.