The memory stick contains names, addresses and dates of birth and includes details of 10,000 people listed as Britain's most serious offenders.

The list also includes 84,000 current prisoners and 33,000 other people whose names are stored on the police national computer.

The Home Office blamed the loss on an "external contractor" who had copied the details from the JTrack database, which is used by the police and other enforcement bodies to keep tabs on offenders once they have been released.

Shadow home secretary Dominic Grieve said the loss showed a massive failure of duty.

"British taxpayers will be absolutely outraged if they are made to pick up the bill for compensation to serious criminals," he said.