A tennis ball filled with cocaine, ecstasy tablets and cannabis was recovered outside The Mount Jail at Bovingdon.

Michael Yearwood, 30, was seen acting suspiciously outside the fence of the jail before he could throw the ball into the compound.

He was challenged by prison officers and ran off dropping the ball, St Albans crown court heard today.

Yearwood was arrested and when the ball was examined it was found to contain 2.63g of cocaine, 20 Ecstasy tablets and 13 and half grams of herbal cannabis, said Alan Landsbury prosecuting.

He told the police he had thought he was delivering mobile phones to inmates at the jail, not drugs.

Yearwood of Redwood Close, Great Leys, Oxford appeared for sentence having pleaded guilty to three counts of possessing drugs with intent to supply on the afternoon of December 9 2006.

He had initially denied the charge and was due to stand trial but changed his plea to guilty.

Defence barrister Alistair Grainger said Yearwood was suffering from a severe cocaine habit at the time. He said he had now stopped using the drug.

He said when he set out that day he had not intended to supply drugs to the prison.

Judge Marie Catterson jailed him for 4 and a half years. She told him: "Supplying drugs to prisoners is particularly serious. The drugs become contraband currency and support an illicit hierarchy and can foster disorder and bullying."