Photo: The Canadian Press - AP

A U.S. prison worker pleaded guilty Tuesday to smuggling hacksaw blades in frozen hamburger meat to two killers who later broke out in a brazen, elaborate escape that captured the world's attention for more than two weeks.

Joyce Mitchell, a tailor shop instructor at Clinton Correctional Facility in northern New York state, was jailed shortly after the intricately staged June 6 escape of Richard Matt and David Sweat. Matt was shot and killed by searchers June 26, about 30 miles west of the prison; Sweat was captured near the Canadian border two days later and sent to another prison.

Mitchell, 51, faces a sentence of 2 1/3 years to 7 years in prison under terms of a plea deal with prosecutors. Sentencing is set for Sept. 28. Her lawyer said his client won't be able to post the bail set by the judge at $100,000 cash or $200,000 bond.

Corrections officials said Tuesday that Mitchell, who was arrested June 12, resigned from her job about two weeks later.

She admitted providing hacksaw blades, chisels, a punch tool and a screwdriver to Matt. Authorities say she became close to the pair, agreed to be their getaway driver and even discussed killing her husband. But she backed out at the last moment, forcing Matt and Sweat to flee on foot after they emerged from a manhole near the maximum-security prison.

Defence attorney Stephen Johnston said Mitchell "got in over her head."

"I think that to a certain extent Matt got her to feeling good about herself, better than she had for a period of time, and she was swept off her feet a bit, for a period," Johnston said. "And then when she realized who she was dealing with everything changed."

Investigators also said Mitchell had discussed killing her husband, Lyle Mitchell, as part of the plot.

Lyle Mitchell was in court Tuesday and declined to speak with an Associated Press reporter afterward.

Authorities said she smuggled the hacksaw blades and other tools into the prison by hiding them in frozen meat she placed in a refrigerator in the tailor shop. They said a corrections officer then took the meat to Sweat and Matt, who were housed in a section where inmates are allowed to cook their meals.

Authorities do not believe the officer knew of the escape plan. He was released on bail after being arrested on charges including promoting prison contraband.

Investigators do not think knowledge of the plot went beyond Matt, Sweat and Mitchell.

Authorities say Matt and Sweat cut through their adjoining cell walls over months, climbed down catwalks to tunnels, broke through a brick wall, cut into and out of a steam pipe and cut a chain holding a manhole cover outside the prison to get away.

Sweat, 35, was serving a life sentence without parole in the killing of a sheriff's deputy. Matt, who turned 49 on Thursday, was doing 25 years to life in the kidnapping, torture and hacksaw dismemberment of his former boss.