Richard Matt, one of two prisoners who have been on the run for three weeks after escaping from a maximum security prison in upstate New York has been shot and killedby police, according to reports.

And authorities are reportedly closing in on his accomplice David Sweat amid reports that gunfire was exchanged near Malone, New York.

The New York Times reported that police officers did not see Sweat, but they heard him running. "They don't have eyes on the guy, but they have a three-mile perimeter around the area," a person with knowledge of the situation told the paper.

Matt, , 49, a convicted killer who broke out from Clinton Correctional Facility with 35-year-old David Sweat, was killed by a fatal gunshot wound, law enforcement sources told the New York Times.

Reports suggest he was shot near Malone, New York State, about 35 miles from Dannemora, a village near the Canadian border, where the prison is located.

Matt was convicted in the 1997 torture, murder and dismemberment of his boss in Tonawanda, New York, and was sentenced to 25 years to life.

Sweat was serving a life sentence after his conviction in the shooting death of a Broome County Sheriff's deputy on July 4, 2002.

Sources told CNN they were "in pursuit" of Sweat, who remains at large.

Two people have been arrested and charged for actions related to the escape, civilian Joyce Mitchell and prison worker Gene Palmer.