Hazel Blears, Secretary of State for Communities and Local Government, may have broken official guidelines on data security after it was revealed that a laptop had been stolen from her constituency office.
The laptop was snatched from her office in Salford and contained a number of sensitive government documents.
This latest incident is one of many such cases of data loss on which the Information Commissioner has promised to crack down.
"It is clear that papers have been sent to Hazel Blears in a way that is not fully consistent with departmental guidance," said her department's top civil servant Peter Housden.
"Thankfully no damage has been done since the documents sent to her were not classified as secret or top secret. And in any event the computer was password protected.
"I have instructed my officials that departmental procedures, guidance and the awareness and accessibility of that guidance, are now strengthened to ensure that this does not happen again."
The case is increasingly being used by opposition MPs to highlight the dangers of the government's plans to build large centralised databases of public information.
The Conservatives have said that the lack of data controls means that these plans must now be re-examined.
"High-profile data theft cases have become rife in recent months," said George Foot, sales and marketing director at Kensington Europe.
"And putting sensitive information such as children's addresses and customers' bank details at risk is not just bad PR for the organisations involved. When Nationwide lost a laptop containing 11 million customer details it was fined £980,000.
"It seems that, even though people know that laptops can be easily stolen or lost, organisations believe that having a password is enough to keep data safe.
"Unfortunately, this will not stop a determined thief from hacking into the computer. The best way to make sure that sensitive data does not fall into the wrong hands is to ensure that the device itself cannot be stolen."
Latest Tesla news: Tesla stock price tanks amid reports of 'widening probe' by SEC and claims the base Model 3 loses money
SEC 'probe' takes its toll on Tesla as new research suggests that Tesla loses $6,000 on every $35,000 Model 3
10nm Cannon Lake Core i3-8121U CPUs make a rare outing with Intel's NUC mini PC
'Notorious' Australian child hacker thought he had executed 'flawless' hack
The former employee says that Tesla fired him for bringing the accusations to management internally