The junior official at the centre of Britain's biggest data security scandal is being protected in a "safe house", it was claimed last night.

As Scotland Yard detectives continued their search for the confidential details of 25 million people, reports suggested the computer specialist had been given a 24-hour "minder" to shield him from media scrutiny and was being put up in a hotel in the North-east of England at taxpayers' expense.

Last month, the official, who works at the Child Benefit Office in Washington, Tyne and Wear, broke security protocol by posting two computer discs, containing the details of every child benefit claimant in the UK, to the National Audit Office in London.

Gordon Brown issued what is thought to have been his first-ever apology from the Commons dispatch box as he ordered a security check across all Whitehall departments. The Prime Minister told MPs he "profoundly regretted and apologised for" the inconvenience and worry caused by the unprecedented blunder that resulted in the loss of the bank details of 7.25 million families, more than 600,000 of whom are in Scotland.

David Cameron accused Mr Brown of presiding over a "systemic" failure of data protection. The Conservative leader said millions of people were now "worrying about the safety of their bank accounts and the security of their family details" and were "angry that the government has failed in its first duty to protect the public".

He sought to load personal responsibility on to the PM, saying the security regime at HM Revenue and Customs had been put in place while Mr Brown was at the Treasury.

Mr Cameron also claimed the public would find it "bizarre" that the UK Government was not willing to "stop and think" about the introduction of ID cards in the wake of the data security blunder.

Mr Brown made clear there was no reason for Alistair Darling to resign, claiming the Chancellor was doing an "excellent" job.

The PM announced that Richard Thomas, the Information Commissioner, would be granted new powers to carry out spot checks on departments to ensure they were doing everything they could to protect the privacy of details given them.