The Scottish Ambulance Service has admitted it has lost a disc containing the personal details of nearly a million emergency calls.
The lost disc contained a record of 894,629 calls to the Ambulance Service in the West of Scotland since February 2006, including phone numbers, patient names and addresses. The disc went missing on 9 June in transit while being couriered by TNT to specialist IT company MIS Emergency Services.
The ambulance service said in a statement: "It would be extremely difficult for anybody to gain access to any meaningful information. All the information was password protected and was protected by high security industry standard encryption."
Health secretary Nicola Sturgeon said the ambulance service had followed guidelines. "The responsibility and the fault lies with TNT."
It is the latest in a list of data losses that have included similar incidents involving discs lost in transit. In May, NHS trust Sandown Health Centre on the Isle of Wight lost computer back-up tapes with more than 38,000 patient records, while being sent by courier to a London-based software company.
Last year, HMRC lost unencrypted discs in the mail that held personal information on 25 million people and 7.2 million families, including names, addresses, dates of birth, Child Benefit numbers, National Insurance numbers and bank or building society account details.
There have also been a number of lost data incidents involving documents left on trains or in pubs, and laptop computers lost by officials or stolen from a minister's constituency office.