A convicted murderer is on the loose after he walked away from a low security prison in the central North Island today and police say drivers in the area should be wary of hitchhikers.

Christopher Thomas Watkins was serving a life sentence at Tongariro Rangipo Prison for a 1988 murder.

Police consider him dangerous and said he should not be approached.

Watkins had been working at the prison when he walked away about 12.15pm.

Staff at the prison's south unit noticed he was missing about 1pm .

Department of Corrections regional manager Terry Buffery said the full details of Watkins' escape were not yet known.

"Public safety is our number one priority, staff notified the police immediately and we are working very closely with them to ensure the rapid recapture of the prisoner." The department was "extremely concerned" about the incident and was investigating, Mr Buffery said.

Prisoners at Tongariro Rangipo Prison had a low security classification.

This meant the prison put a focus on prisoner employment and training to help rehabilitate prisoners for release, with work skills and habits, he said.

Watkins was undertaking on-site employment when he walked away, Mr Buffery said.

Police had no idea where he was heading at this stage and asked anyone travelling through the central North Island to be wary of hitchhikers, Acting Senior Sergeant Neale Saunders of Turangi police said.

Any residents in the area should be vigilant with securing property and vehicles.

Police want to hear about anything suspicious.

Watkins was described as an average build Caucasian male, about 165cm tall.

He was last seen wearing a green polar fleece and a denim jacket.

Watkins had been eligible for parole in 1998.

- NZPA