Oz officials left baffled by prisoners breaking out regularly to commit crime

Australian police and prison officials are investigating claims that two prison inmates are breaking out of prison secretly, committing crimes and then sneaking back in undetected.

The inquiry was launched after two armed men wearing prison greens stormed a Domino's pizza outlet in Kelso, near Bathurst, last Saturday morning, forcing staff to the ground before raiding the cash register and fleeing with a small amount of money.

A white Toyota HiLux 4WD matching the description of their escape vehicle was found abandoned hours later at the nearby Oberon Correctional Centre, a minimum security centre for men aged between 18 and 25 years, News.com.au reported.

The vehicle had been stolen from a property at Porters Retreat, south of Oberon, on January 17, fuelling fears the inmates had broken out of and back into jail a number of times.

A timber harvester operator reported seeing the HiLux parked in scrub on the eve of the hold-up, before again spotting it parked 500m from the prison's boundary fence on Saturday afternoon.

He called the ute's owner after finding his details in the vehicle.

The owner then contacted prison staff to say he had found a homemade gun and a knife in the ute.

Another farmer also reported a vacant house on his land had been broken into, with doors ripped off cupboards and blankets removed.

He believed the offenders had also tried to steal his ute.

Concerned that prisoners had escaped and were using the house as a base, he contacted staff at the Oberon jail to see if there had been any escapes but was told "all inmates are accounted for".

A NSW Corrective Services Department spokesman confirmed an investigation was under way but didn't comment on the bizarre events.

A NSW Police statement said investigations were under way into a robbery at Kelso and an "alleged incident" at Oberon jail. (ANI)