Britain's National Health Service (NHS) has reportedly misplaced the medical records of 168,000 individuals, of which 160,000 are said to relate to children.
According to The Sun, ten trusts have owned up to mislaying the patients' files in the latest in a series of public sector data blunders.
Last night Joyce Robins, of support group Patient Care, was quoted as saying: "I think it's the tip of the iceberg because there is such carelessness within the NHS. It's always impossible to hold anyone to account."
The lost details could include patients' most personal secrets, including health records, the ex-directory phone number to HIV status, she warned.
The medical details of 160,000 children were lost in the post by City and Hackney Primary Care Trust in East London. A further 8,000 files have been lost by other authorities, including Bolton Royal Hospital, Sutton and Merton PCT, Sefton Merseyside PCT, Mid-Essex Care Trust, Gloucester Partnership Foundation Trust, and Norfolk and Norwich.
The East and North Hertfordshire Trust reported a loss but has since found the missing data. Maidstone and Tunbridge Wells NHS Trust blundered twice ó meaning there have been ten breaches in total.
A Department of Health spokesman said the disc containing the children's details was encrypted and that only a small proportion of the other files involved clinical data.
He said: "There is no evidence of any data falling into the wrong hands."
Last night public health minister Dawn Primarolo said the department was working to resolve the matter quickly.
It is the latest missing data scandal to hit the Gordon Brown Government. Last month it was revealed that records of 25 million child benefit claimants were missing. And, last week, three million drivers had their files lost.