Nicola Sturgeon, the Scottish Health Secretary, was under pressure last night to make an emergency statement to MSPs after the embarrassing loss of confidential patient data from the Scottish Ambulance Service.

A disc containing information relating to almost 1,000 emergency call outs, including the names and addresses of patients, went missing earlier this month while the courier company TNT was transporting it from the ambulance service's emergency medical dispatch centre in Paisley. Despite an extensive search, the disc had still not been recovered yesterday.

The Scottish government did not issue a statement revealing that the disc had gone missing until yesterday - four days after it was alerted to the embarrassing loss.

A Scottish Government spokesman said: “The Scottish Ambulance Service informed us late on Thursday, June 19, that contact information being transported by TNT from its Paisley emergency medical dispatch centre was missing.”

He added: “The courier company has accepted full responsibility for the loss and we are confident that this is an unfortunate but isolated incident and that the ambulance service took all necessary steps to comply with data protection regulations.”

The Scottish Ambulance Service said yesterday that the disc contained a copy of records of 894,629 calls to the service's Paisley centre since February 2006, including the addresses of incidents, some phone numbers and some patient names. It was fully encrypted and password protected.

The service said in a statement yesterday: “Given the security measures and the complex structure of the database it would be extremely difficult to gain access to any meaningful information.”

The missing disc was sent on June 9 to MIS Emergency Services Ltd in Manchester, the company that supplies the IT system used in the ambulance service's three centres. The information on the disc was to be used in the development of a command and control system for the service.

It was a further ten days before the Scottish government was informed.

Pauline Moore, the acting chief executive of the ambulance service, said: “All security procedures for the transfer of data were followed. However, TNT have advised that they cannot find the package ... we have established a phoneline [0800 783 4914 - 7am-10pm] for anyone who may have concerns to call and discuss them.”

She added: “The secure management of patient data is vitally important. We have followed recommended guidelines for the transfer of data and it is disappointing and regrettable that this has happened. We are currently addressing the issue with TNT.”

Margaret Curran, Labour's Shadow Health Secretary, last night called on Ms Sturgeon to make a statement to MSPs. She said: “The loss of such personal details will be deeply worrying for many Scots. Nicola Sturgeon must now take decisive action to reassure the public that everything is being done to retrieve the information.

“The Scottish government has delayed for two weeks before admitting the loss of nearly 900,000 personal records. Nicola Sturgeon must now make an emergency statement to Parliament setting out all the facts.”

David McLetchie, the Scottish Conservatives' Chief Whip, said that the government statement raised more questions than answers.

He said: “We can only assume it is of a relatively serious nature, otherwise the government would not have issued a statement about the loss. However, we need to know more than we are being told, and particularly whether or not any patients or families who might be affected by this breach have been notified.”

The lost data is a further blow to the Scottish Ambulance Service, which is at the centre of an independent investigation into allegations of bullying and harassment.

Senior officials at the organisation have taken voluntary leave while the complaints are looked into.

The incident is also more bad news for Ms Sturgeon, who has been under pressure to explain a delay in investigating the outbreak of the C. difficile bug at the Vale of Leven hospital in Alexandria, which claimed the lives of nine patients.

The ambulance service records are the latest in an inglorious spate of official carelessness that started last September when details of 15,000 people went missing after HM Revenue and Customs (HMRC) sent them to the insurer Standard Life.

In October two CDs containing unencrypted details of 25 million child benefit claimants were lost when being sent - unregistered and not recorded - through the post by a junior HMRC official to the National Audit Office.

In December Ruth Kelly, the Transport Secretary, admitted that personal details of three million learner drivers had been lost by the DVLA after a computer went missing in the US state of Iowa. The same month, HMRC lost the names, postcodes and National Insurance numbers of 6,500 private pension holders on a computer cartridge at a centre in Cardiff. And nine NHS trusts in England admitted losing data on hundreds of thousands of patients, including 160,000 children's names and addresses, after a disc failed to arrive at an east London hospital.

Last week Hazel Blears was in trouble after her laptop containing sensitive Cabinet documents on religious extremism was stolen, and a senior staff member at the Cabinet Office was suspended for leaving top-secret documents on a train.

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