Joyce Mitchell

Joyce Mitchell, left, appears in a CNN report alongside the Upstate NY prison escapees she's believed to have assisted.

(CNN video still)

Joyce Mitchell, left, appears in a CNN report about the Upstate NY prison escapees she may have assisted.

The Upstate New York prison worker suspected of helping two convicted killers escape has been called a "cheater" by her ex-husband.

Joyce Mitchell has been questioned by authorities in the investigation as to how David Sweat and Richard Matt broke out of Clinton Correctional Facility in Dannemora, N.Y. The pair escaped "Shawshank Redemption"-style by using power tools to cut through steel walls and a steam pipe and exit through a manhole cover on the street.

Mitchell, 51, also known as "Tillie," was a supervisor in the Dannemora prison's tailoring department, where both inmates worked. She's believed to have agreed to drive the getaway car after being wooed by Matt, but changed her mind at the last minute and was hospitalized due to panic attacks.

New York State Police Superintendent Joseph D'Amico confirmed to the Associated Press on Wednesday that she befriended the killers and "may have had some role in assisting them." She's reportedly cooperating in the investigation, but it's unclear what charges she may face.

Mitchell's ex-husband, Tobey Premo, isn't surprised at her possible involvement.

The 51-year-old Massena farmer was her high school sweetheart in St. Regis Falls, some 50 miles west of Dannemora. They were married for five years until she had at least two affairs, according to the Daily Mail.

"Sure she cheated on me," Premo told the publication on Wednesday. "It wasn't just with Lyle, her husband now, but with another guy she worked with. I found out because his girlfriend came to me and told me about it."

Lyle Mitchell also works at the Clinton County facility as an industrial training supervisor. Lyle adopted Premo's biological son with Tillie, Tobey Mitchell, and Premo says he hasn't had contact with either of them since the split.

Tobey Mitchell told NBC News earlier this week that he doesn't believe his mother would willingly help the convicts.

"She's not going to risk her life or other people's lives to help these guys escape," he told the TV station. "She's always been a good person, and anyone will tell you, [my parents] are the nicest people."

Premo disagreed. "She cheated on me, so I could see her falling for someone in prison," he told the Daily Mail.

Matt, 48, and Sweat, 34, escaped overnight Friday from the maximum security prison located about 20 miles south of the Canadian border.New York State Police closed a stretch of Route 374 east of Dannemora on Wednesday night to search for the pair.

Matt is described as a white male, 6-feet tall, 210 pounds, with black hair and hazel eyes. He has tattoos on his back that say "Mexico Forever", a heart on his chest and left shoulder, and a Marine Corps insignia on his right shoulder.

Sweat is described as a white male, 5-feet, 11-inches tall, 165 pounds, with brown hair and green eyes. He has tattoos on his left bicep and his right fingers.

Both escapees are considered extremely dangerous. Sweat was serving a life sentence for shooting the sheriff's deputy 15 times in 2002. Matt was in prison for the kidnapping, murder and dismemberment of a man who had fired him from his job at a food warehouse.

The state has offered a $100,000 reward for information leading to the capture of both men. People with information can call 1-800-GIVE-TIP.