A female prison worker identified as Joyce Mitchell has been questioned in the investigation of the escape of two convicted murderers from a maximum security prison in upstate New York over the weekend.

Officials say the prisoners -- Richard Matt, 49, and David Sweat, 35 -- used power tools to cuts through steel walls and underground pipes in their escape route at the Clinton Correctional Facility in Dannemora. They then broke through a manhole one block away from the penitentiary around 5:30 a.m. Saturday morning. Based on evidence, it seems likely that their dramatic escape was made possible with inside help.

According to state records, Mitchell works as an industrial training supervisor that supervises inmate work assignments. ABC News reports that sources say Mitchell was questioned on Sunday.

Following the prison break, New York Gov. Andrew Cuomo said inmates Matt and Sweat must have had help in carrying out the intricate plot.

"They wouldn't have had the equipment on their own, that's for sure," Cuomo told CNN of the convicted killers.

The pair tricked the guards by arranging things in the bunks to look "like people were sleeping ... with these sweatshirt hoodies on," Cuomo said.

The convicts also left a yellow sticky note with a smiley face that read, "Have a Nice Day!"

Around 250 law enforcement officials are searching for Matt and Sweat, who are both serving lengthy sentences for hard core crimes at the Clinton Correctional Facility. The prison has been dubbed "Little Siberia" due to its location in a sparsely populated northeast corner of New York, about 25 miles from the Canadian border.

"They could be literally anywhere," Maj. Charles E. Guess of the New York State Police said.

New York State officials announced a $100,000 reward for anyone with information leading to their apprehension and arrest.