Six laptops containing information on around 20,000 patients have been stolen from a top London teaching hospital.

The laptops include the names, dates of birth and postcodes of patients at St George's Hospital in Tooting, south London, a spokeswoman said.

She said: "The Trust has written today to every patient, apologising for the potential risk to their confidentiality. All data on the laptops was password-protected and personal information such as postcode was hidden, although the patient's name and hospital number was shown.

"The Trust acknowledges that patient data should not have been stored on laptops. This was done as a temporary measure because of a problem with the computer network. However, the laptops were in a secure area under lock and key.

"The data was being used to monitor and reduce waiting times at the hospital."

Earlier, it emerged that a laptop containing confidential information about 11,000 patients had been stolen from a GP's home in Wolverhampton.

Contrary to Department of Health guidelines, the information was not encrypted, which would have made it unreadable without a special code to unscramble it.

The laptop was among items stolen in a recent burglary at the home of the unnamed doctor, who works at the Castlecroft Medical Practice.

The information on the computer, which belongs to the practice, included patients' names, dates of birth, addresses, contact details and confidential medical records.

The practice has written to all of its 11,000 patients to inform them that information about them was on the stolen computer.

Dr Peter Wagstaff, senior partner at the practice, said: "The practice is treating this issue very seriously and we are extremely sorry for any distress or concern that it may cause our patients.

"Though not encrypted, the confidential information on the laptop was protected by a complex password system, which only a person with specialist computer knowledge would be able to crack."