Man 'tried to dig tunnel' under Goulburn maximum security jail

An investigation is underway into reports an inmate allegedly tried to dig a tunnel under Goulburn jail.

Corrective Services NSW said a "manmade cavity" was found beneath a cabinet n a furniture workshop section of the maximum-security prison.

"The cavity was in the furniture workshop more than 100m from the outside walls of the prison. The cavity is about 600mm deep and its entrance is 400mm by 180mm," a spokesman said.

"It is not yet known who made the cavity or its intended use."

The furniture workshop will remain closed to inmates until investigations have been finalised.

According to a whistleblower who contacted 2GB radio presenter Ray Hadley, a convicted murderer with a long sentence has been accused of digging the tunnel.

The radio station reported that staff also found supporter clothing from the Parramatta Eels NRL club in the tunnel.

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