The security service did an immediate risk assessment and concluded there had been no breach of national security

Home Office

Home Office officials have admitted the papers are still missing and appealed for anyone who found them to hand them back.

British spies have earned a reputation recently for mislaying their property.

A series of similar blunders have included a laptop computer being stolen from another MI5 operative, an MI6 spy losing his computer in a tapas bar and a senior Army official's laptop being stolen at Heathrow Airport.

'No risk'

Armed forces minister John Spellar, the government minister in charge of Britain's nuclear secrets, had his laptop stolen during a burglary at his home in Kent in March.

A Home Office spokeswoman urged anyone who found the latest missing papers to hand them in to their nearest police station.

She said: "We understand that some papers were lost. We would appeal to anybody who knows the whereabouts of these to come forward and contact the police.

"As is normal procedure the security service did an immediate risk assessment and concluded there had been no breach of national security.

"The matter was reported to the police and they are aware of the loss.

"We have established procedures for looking into the loss of items and these procedure are constantly under review."