Six laptops containing personal details of 20,000 patients have been stolen from a south London hospital.
The computers were taken from a locked cabinet at St George's Hospital in Tooting earlier this month, police have revealed.
Patient information kept on the laptops includes brief medical notes, names, dates of birth and postcodes, according to BBC reports.
The hospital said the data was stored on laptops as a temporary measure because of a problem with the computer network.
Although the data is said to be password protected, the theft once more raises questions about the security of data held by government agencies.
The news comes just a day after it emerged that thieves stole a computer from the constituency office of Hazel Blears, secretary of state for communities and local government, last Saturday.