The government has admitted that it has lost yet more data, after two discs from the Driver and Vehicle Agency in Northern Ireland got lost in the post.

The discs were being sent to the agency's headquarters in Swansea and contained the details on 7,685 vehicles and more than 6,000 vehicle owners. The data includes the owner's name, address, registration mark of the vehicle, chassis number, make and colour.

Northern Ireland's Environment Minister Arlene Foster said there was little chance of the discs turning up, but that no financial information was stored on them.

Alan Bentley, regional vice president of security managers Lumension (formerly PatchLink) commented: "This latest security blunder will no doubt undermine consumer confidence. Unless decisive and effective measures are taken to protect data leakage, exposure to identity theft will get worse. Unfortunately, even the most vigilant consumers are not immune – it is no use shredding your personal details if they keep ending up lost in the postal system.

"The proliferation of data loss due to the inappropriate or sometimes criminal use of removable media devices has reached alarming levels and these publicised incidents are becoming commonplace. The only way to eliminate data loss from removable devices is to take control of the flow of inbound and outbound data from your endpoints and encrypt the data during transmission."

One of the problems is that the data on the discs is unencrypted and can be accessed by anyone without the need to crack or guess a password.

Brendan Magee, chief executive of the Driver and Vehicle Agency, told the BBC he understood why customers would be concerned.

"We were undertaking a review of how we transmit all this information. Unfortunately, this incident had taken place before we completed the review and we deeply regret it and we regret the embarrassment we caused to the customers. "

"It wasn't encrypted. This was one of the problems we had identified through our review, that this was an actual weakness. We are now looking at alternative methods of transporting this information."