Four mentally disabled people have been found locked in a basement in Philadelphia, US.

One of the victims was found chained to a radiator in the room, described by police as a “dungeon.”

The building’s landlord, Turgut Gozleveli, found the four people in the disgusting 10ft x 15ft boiler room amid bedding, a flat board with a pillow and a single bucket for the group to urinate in.

There was not enough room in the dungeon for an adult to stand upright in.

Gozleveli, 71, made the discovery while he was collecting tools from the basement. He heard dogs barking and a chain locking a door to another room, which he went to inspect.

He said: “I asked them what they are doing here, and how they got in. There was no communication. I asked questions and I didn’t get any answers.”

Gozleveli freed the  chained man and called the police.

The malnourished victims, three men and one woman, were taken to a hospital and are receiving medial attention and counselling.

All four victims, aged 29 to 41, are said to have the mental capacity of 10-year-olds and as such, interviewing them has proved difficult, according to Ray Evers, of Philadelphia police.

“We have no idea who some of these people are,” Evers said.

Three people have been accused of locking them up so as to collect the victims’ disability benefits. They have been charged with kidnapping, aggravated assault, false imprisonment and other related offences.

The suspected ringleader, Linda Weston, is alleged to have masqueraded as the victims’ caregiver in order to commit fraud.

Police said Weston was in possession of up to fifty ID records, including power of attorney paperwork and social security numbers, when she was arrested, and may have victimised dozens of other people.

At least two of the victims are known to have travelled with Weston, moving from various cities in Texas and Florida.

They may have been held captive in cities throughout the United States for up to eleven years, said Sergeant Joseph Green.

“This is just a horror story,” he said.

“They were abused physically and emotionally.”

The other two victims have been with Weston since February, and all four victims arrived in Philadelphia at some date earlier this month.

Weston will appear in court on Thursday. Police said she was aided by homeless man Eddie Wright, 51, and 48-year-old Philadelphia resident Gregory Thomas.

Bail was set at $2.5m (£1.6m) and has not been posted.