The Scottish Ambulance Service has lost data relating to almost a million emergency calls including the name and addresses of patients, in the latest public sector data loss scandal.

The disc went missing while courier TNT was transporting it to MIS Emergency Services, the company that supplies the IT system used in the ambulance service's three centres.

The disc – which was encrypted – 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.

“Given the security measures and the complex structure of the database it would be extremely difficult to gain access to any meaningful information," said a spokesman for the Scottish Ambulance Service.

The information contained on the disc was to be used in the development of the service's command and control systems.