Hamilton police have arrested four people after finding a 22-year-old man with a mental disability near death in an attic apartment.

The man was allegedly lured into an attic apartment in a triplex on Aurora Street in north-central Hamilton and held there for more than three weeks, according to police.

"During that time, he was bound, beaten, burned over several areas of his body, and at different points turned over bank info, and money was withdrawn from his account," said Hamilton police Supt. Bill Stewart.

Police said they discovered the victim on Saturday when responding to an unrelated call about a dispute between the tenants of the apartment and their neighbours below.

The man suffered life-threatening injuries, Stewart said, including a fractured skull and burns all over his body. He was also allegedly bound for long periods of time while the tenants were out of the residence.

When he was found, he was suffering from "toxic" blood levels and likely would have died within 48 hours if he hadn't been discovered, Stewart said.

"I've been in police for 32 years, and this was some of the most disturbing incidents and allegations I've been exposed to," Stewart said. "It's very disturbing, and it's quite disgusting when you hear of all the details involved."

Aimee Morin, who resides below the apartment where the victim was found, said she had heard loud music and cries of "help, help, ow that hurts."

Morin said she was shocked to find out that other tenants had allegedly entrapped a man in their residence.

"It was gross," Morin said. "Why would somebody do that to a guy? That's wrong."

Dorian Pollard, who lives on the ground floor, said he never heard anything coming from the attic that would have raised concern.

"They went out late at night," Pollard said. "I never heard anything early in the morning, so when all this transpired, it came as a big shock."

The victim lives alone on a disability allowance and had not been reported missing. He is recovering in hospital, police said.

Hamilton residents Stanley Brown, 30, Nathaniel Jug, 22, and Dakota Thompson, 20, appeared separately in court on Wednesday. The three are charged with forcible confinement, aggravated assault, aggravated sexual assault, threatening death and robbery.

Police have also arrested a 17-year-old from Port Colborne, Ont. He faces the same charges.

Thompson, Brown and Jug were remanded in custody for future bail hearings. Thompson is to appear in court on Thursday while Jug was remanded to Friday.

Police said the investigation is continuing.

With files from the Canadian Press