The FBI has launched an investigation into possible broader corruption at the Clinton Correctional Facility in upstate New York, law enforcement officials briefed on the probe told CNN on Monday.
The investigation is looking into possible drug trafficking and other criminal behavior among prison employees and inmates, the officials said.
It comes as a result of evidence uncovered during the investigation of the escape of convicted killers Richard Matt and David Sweat.
Some employees interviewed have told investigators about heroin use among prisoners, and the role of employees in the drug trade.