HORRIFYING pictures reveal the grim interior of a “House of Horrors” where a man was allegedly held captive by his cruel stepmom for 20 years.

Kimberly Sullivan, 56, is accused of holding her unnamed stepson captive inside a small room since he was 11 years old, depriving him of food and subjecting him to relentless abuse.

Sullivan allegedly left the victim “severely emaciated” — weighing just 68 pounds — and “akin to an Auschwitz survivor”, said Waterbury police who shared photos of the house on Monday.

Shocking pictures show a “house of horrors”, with a broken ceiling and floorboards, junk and rubbish piled high in almost every room, as well as carpeted areas covered in dirt and trash.

One photo of a bathroom shows broken wall insulation, glass and cardboard boxes on the floor.

Pictures also reveal walls charred black from the fire that the victim set, using printer paper and hand sanitizer, in a desperate attempt to escape on February 17.

The extent of the property’s dire conditions can be seen in more than 100 photos which Connecticut television station WFSB received from Waterbury police.

The now 32-year-old man told authorities that his captivity first began aged 11, when his stepmom locked him in a room with limited food and water and without heat or air conditioning.

Due to a lack of dental care, he said that his teeth would break off on the occasions that he did eat.

He told police that he had to dispose of his waste through various methods, including using a series of straws that led to a hole in a window.

Sometimes, he would be locked away for 24 hours straight, police said.

When the man attended school, he would reportedly ask his classmates for food, steal food and eat out of the garbage.

The fire, which the victim lit in his room, was successful in bringing his alleged captivity to the attention of authorities, as firefighters rushed to the scene.

Medical personnel treated the man for smoke inhalation and diagnosed him with post-traumatic stress disorder and depression.

They reported that the 5 foot 9 man weighed a mere 68 pounds — the average weight of a 9-year-old boy.

The fire did not reach the parts of the house which appear to be inhabited by Sullivan.

Sullivan, who was arrested on March 13, pleaded not guilty to assault, kidnapping and cruelty charges.

She has been released on bail after posting a $300,000 bond and maintains her innocence.

Her attorney Ioannis A. Kaloidis told Daily Mail that it was the boy’s biological father Kregg, who was responsible for the “decisions” about his life.

According to authorities, Kregg died last year and the victim’s biological mother has not been a part of his life.

In terms of his personal hygiene, Sullivan claimed that she encouraged him to wash but “couldn’t force” him to do so.

Kaloidis said earlier this week: “She completely maintains her innocence, from our perspective. These allegations are not true. They are outlandish.

“She was blown away when she heard these allegations.”