The NHS laptop discharged itself on 8 January from the outpatient department at Russells Hall Hospital in Dudley.

It contained the details of 5,123 patients who were part of an anticoagulation clinic, which treats people who suffer from blood-thinning.

The incident came to light because the Dudley Group of Hospitals sent letters to all of the people whose details were stolen.

Data on the laptop wasn’t encrypted, but the hospital claims passwords on the machine itself and on the database of patient data mean it is protected.

However, spokesman Paul Farenden said this was clearly “a serious issue."

"We take precautions to try to protect all the IT equipment in our hospitals from theft,” he said.

“But given that this is a public building with thousands of people accessing it every day, there are inevitably practical difficulties around security."