Prison guards snatched 241 banned mobile phones from inmates at Ford Prison last year in the battle to end drug dealing behind bars.

Last year's haul was revealed by Home Secretary Charles Clarke under the Freedom of Information Act.

The haul at Ford - an open prison - was the largest in any jail in the country and inmates have been stashing more phones each year. In 2004 146 were confiscated and two years before that wardens seized just two.

The Prison Service insisted tough measures were under way to deal with the problem.

Having a mobile phone is a breach of prison rules and security, as phones are often used by prisoners to deal drugs and harass hostile witnesses.

A spokesman for the prison service said this could be the case at Ford prison.

He said: "There could be cases of either, both or neither. There are potentially lots of different reasons why they could be in there and we can't comment on 214 different cases.

"Security is paramount in prisons and the Prison Service takes security breaches very seriously.

"There are rigorous search systems in place for prisoners and any visitors in order to prevent phones entering prisons and tough sanctions are taken against those found with mobile phones inside prisons.

"HMP Ford is an open prison, which will make it easier for prisoners to smuggle phones into the prison.

"However, the high numbers of phones recovered demonstrates how seriously the governor and staff are taking this."

Ford has been criticised for allowing day release to convicted murderers.

In February the teenage murderer of headteacher Philip Lawrence was allowed out to see family and, a month earlier, child killer David McGreavy was allowed to wander round Liverpool in a break from prison.

Last year The Argus reported the prison had been criticised for being more like a holiday camp.

Ford Prison Officers' Association said inmates were able to go to Tesco to shop for alcohol and groceries and prisoners were coining the jail "HMP Butlins".

In a separate incident it was found four prisoners were employed by Stagecoach to ferry passengers, including schoolchildren, around Arundel, Worthing and Chichester.

An average of 20 mobile phones were seized in British prisons last year. At Lewes Prison 29 handsets were confiscated.