Gordon Brown has ordered a review into the huge security lapse after revelations that Britain's tax authority has lost data on 25 million people. British Prime Minister Gordon Brown apologised on Wednesday (November 21) for the loss of millions of Britons' personal details and ordered a review into the huge security lapse. Brown also said the Information Commissioner Richard Thomas would get new powers to carry out spot-checks on government departments' security. He was addressing parliament after the British government said the tax authority, HM Revenue and Customs (HMRC), had lost data on 25 million people -- potentially the largest data security lapse in British history. It exposed them to the risk of identity theft and bank fraud. "I profoundly regret and apologise for the inconvenience and worries that have been caused to millions of families who receive child benefit," Brown said. "When mistakes happen in enforcing procedures we have a duty to do whatever we can to protect the public and that's why bank accounts have been checked now for fraudulent activities." The lapse dealt a heavy blow to Brown's government, which is already being batted by criticism of its handling of Northern Rock banking debacle -- the first run on a British bank in a century. Two computer discs containing information on 25 million Britons disappeared after being sent via courier TNT from HMRC. Brown stressed that there was no evidence that the data had fallen into criminal hands, but urged Britons to keep a close eye on their bank accounts. Opposition Conservatives said many people would be worried. "I have to say to the Prime Minister, if a junior official in an organisation can access so much information and send it not once, not twice, but three times, that is evidence of systemic failure," Conservative leader David Cameron said. "But they will not just be worried, they will be angry that the government has failed in its first duty to protect the public." Workers in London's financial district Canary Wharf said they were worried by the security breach.