The British Broadcasting Corp. says that a new batch of sensitive government data has been lost.
The BBC says a contractor working for Britain's Home Office misplaced information relating to thousands of criminals.
Britain's government has suffered a series of highly embarrassing security breaches over the past year.
Two sets of secret government files were left on commuter trains in June. Recently officials have also lost track of computers, discs and other records carrying information on thousands of prospective military recruits, driving-test candidates and hospital patients. In November, tax officials said they lost discs containing information on 25 million people.
Phones at the Home Office rang unanswered late Thursday.