Nine NHS trusts have admitted losing patient records with hundreds of thousands of adults and children possibly affected by the security breach.
Though the Department of Health (DoH) says patients have been informed of the error and that there is no evidence data has fallen into the wrong hands, it follows the loss of the confidential details of 25 million child benefit claimants by HM Revenue and Customs.
In what is emerging as another embarrassing expose of government handling of sensitive data, the Sunday Mirror has reported that one of the security breaches involves the loss of details regarding 160,000 children by City and Hackney Primary Care Trust (PCT) after a computer disc failed to arrive at its east London destination.
The other trusts involved are Bolton Royal Hospital, Sutton and Merton PCT, Sefton Merseyside PCT, Mid-Essex Care Trust, Norfolk and Norwich and Gloucester Partnership Foundation Trust.
And Maidstone and Tunbridge Wells NHS trust has reported two cases of misplaced discs to the DoH meaning that ten cases have occurred in total.
A DoH spokesperson said: "Since the recent heightened concern about data protection a small number of trusts [nine] have reported breaches of their own security rules.
"There are strict guidelines and procedures for dealing with such breaches. Trusts have an obligation to inform patients where appropriate.
"There is no evidence of any data falling into the wrong hands. Investigations are under way in all the trusts involved and action will be taken against anyone who has failed to fulfil their legal responsibilities."
Since the HM Revenue and Customs discs containing child benefit data went missing, it has also emerged that three million motorists' details have been lost in transit in Iowa in the US Midwest.