HM Revenue and Customs (HMRC) has lost computer disks containing confidential details of 25 million child benefit recipients.
The organisation says it does not believe the records - names, addresses, dates of birth and bank accounts - have fallen into the wrong hands. This is not the first time it has lost sensitive information.
STANDARD LIFE CUSTOMERS, NOVEMBER 2007
More than 15,000 Standard Life customers were put at risk of fraud after a courier lost a computer disk containing personal information.
The data was on a computer disk sent from the HMRC National Insurance contributions office in Newcastle to the insurer's headquarters in Edinburgh.
But the disk containing names, national insurance numbers, dates of birth and pension data never arrived.
HMRC routinely sends computer disks containing personal data on taxpayers to the insurance companies that hold their pensions.
LAPTOP STOLEN, OCTOBER 2007
A laptop computer holding sensitive information was stolen from the boot of a car belonging to an HRMC worker, putting hundreds of people at risk of fraud.
A staff member had been using the PC for a routine audit of tax information from several investment firms.
HMRC apologised for the breach, but said data on the PC had been stored securely.
It refused to comment on how many individuals were at risk, or how many financial institutions had their data stolen.
But inquiries by the BBC suggested the computer held data on around 400 customers with high value individual savings accounts (ISAs), at each of five different companies - including Standard Life and Liontrust.
WATCHDOG PROBE, NOVEMBER 2007
An investigation by the BBC's Watchdog programme uncovered cases where mistakes by HMRC caused personal details to be sent to the wrong people.
The HMRC put together a dossier on Eric Tizzard's with details including his National Insurance number, date of birth, and every address he has ever worked and lived at.
But then they sent it all to the wrong person.
Identity fraud expert Julian Evans told the programme that with the details, someone could easily have applied for a credit card, loan or mortgage in Eric's name.
They could even access his bank account and withdraw money.
DOCUMENTS FOUND ON STREET, APRIL 2007
Documents found in Nottingham contained sensitive information and had been stamped by HRMC.
One gave details of the training of a customs officer, including details of interviews with passengers suspected of smuggling cigarettes via an airport.
HMRC said it reacted urgently and was investigating the matter.
The documents, found by a BBC reporter, included a VAT return of a man in Norwich, which showed how much he paid for the November 2005 to May 2006 period and his name and address.
UBS CUSTOMERS, SEPTEMBER 2005
HRMC lost sensitive account information belonging to customers of investment bank UBS Laing and Cruickshank.
It lost a computer disk sent by the bank, which contained address and account details of UBS's Personal Equity Plan (Pep) investors.
The bank offered to change the account details of customers whose personal information was on the disc.
Customer information on the data disc included addresses, dates of birth, national insurance numbers, UBS account numbers and the value of their Peps.
It is not clear how many UBS customers had their account details on the CD-Rom.