A prison officer who smuggled more than 500 worth of drugs into jail in his lunchbox was jailed for 3T years.

Mark Schooley, 28, of Laurel Close, Carterton, took drugs into the jail four times after pressure from a gang of prisoners known as The Untouchables.

Robert Spencer-Bernard, prosecuting, told Oxford Crown Court that police officers became suspicious about drugs at Bullingdon Prison, near Bicester, and mounted an operation to target Schooley. He said cameras in the car park were used to observe an Audi as it pulled up at 3.15pm on May 14 last year. The driver got out, went into the visitors' centre for a minute or two, left and got into Schooley's unlocked car.

Mr Spencer-Bernard said after a couple of minutes he got back in the Audi and drove away.

Police stopped Schooley the following morning and he said he had drugs in his lunchbox.

Schooley admitted conspiring to take three ounces of cannabis into the prison and asked for three other similar offences to be taken into consideration. Ian Lawrie, defending, said Schooley was a trainee officer who became ensnared and intimidated by the gang into helping them.

Judge Tom Corrie said: "It must have been plain to you that drugs were a valuable commodity in prison, more so than outside, and there was a trade in it by the more powerful and influential inmates at the expense of the vulnerable ones."

He said Schooley had breached his trust and duty as a prison officer. Schooley gave evidence for the prosecution in the trial of four people accused of conspiracy to supply drugs.

James Boyle, 34, of Smethwick, and Gary Barr, 34, of Walmley, Sutton Coldfield, were acquitted of the charges.

Michael Nolan, 32, of Wolverhampton, and Tracey Gill, 24, of Smethwick, face a retrial.