SECURITY is being reviewed after an intruder got into a nuclear power plant.

Guards discovered the man inside offices at Hartlepool Power Station, in the middle of the night.

Owner British Energy said it was thought he scaled a perimeter fence and got into an administration area.

A spokeswoman said: "We are already reviewing our security procedures. This has caused us to have a good look at things. It looks as though he gained access by climbing the perimieter fence. It has video surveillance and is alarmed.

"That is just one part of a multi-layered security system.

"The guards picked up on that alarm and the man was apprehended."

British Energy and the Government announced that armed guards would be deployed at all the UK's nine nuclear plants, including Hartlepool, by next year.

In December, concerns were raised that rabbit hunters could scale the fence to go hunting.

At the time, British Energy said it would increase security.

Independent Councillor Mike Turner, who has previously raised concerns, said: "Although the intruder was not caught by security guards in the most sensitive part of the station and had not entered any of the most sensitive zones, I hope British Energy and the Government's nuclear watchdog will learn lessons from this incident and make the improvements.

"I would suggest speeding up the introduction of the armed guards."

Detective Sergeant Matt Mason, of Hartlepool police, said a 30-year-old man was arrested at about 2am on Thursday at the plant.

The intruder, who was unarmed, was questioned and released without charge into the care of the University Hospital of Hartlepool for assessment.