A council is writing to almost 40,000 customers after a laptop containing personal data was stolen.
Glasgow City Council is to issue a letter to 37,835 individuals and companies affected by the theft, which included bank details of more than 16,000 people.
The information relates to 17,692 companies and 20,143 individuals. It includes names and addresses, and, in the case of 16,451 customers, bank account details. The bank account details relate to 10,382 companies and 6069 individuals.
Affected customers include suppliers, people receiving winter fuel payments and people in receipt of care grants.
The laptop was one of two stolen during a break-in at the council offices in Cochrane Street, Glasgow, sometime between Monday May 28 and Tuesday May 29.
The full extent of the data loss did not become apparent until Wednesday, June 6. No personal data was stored on the second laptop.
Although it was not encrypted, the laptop was password-protected.
The council has contacted the Information Commissioner and Strathclyde Police, and will be liaising with customers' banks, where appropriate. The council's Internal Audit section is also carrying out a full investigation.
A council spokesman said: "We are in the process of writing to the people affected by this theft to alert them to the data loss and offer them advice about what steps they might need to take. We've also provided them with a phone number they can use to contact us if they have any questions.
"We are sorry that this has happened and apologise for the inconvenience it has caused. Anyone with any information on the theft should contact Strathclyde Police. Customers should remember that no one from the council would ever call at their home or telephone them to ask for personal information, such as banking details. A bank will never ask for a customer's PIN or for a whole security number or password.
"If affected customers have any questions, they can contact us on 0141 287 0400 between 9am and 5pm, Monday to Friday. Anyone with information on the theft or who wants to report suspicious activity should contact their local police office."
Glasgow SNP group leader Graeme Hendry commented: "This is a matter of deep concern, with the personal details of some very vulnerable people amongst those stolen from council property.
"This is not the first time that such a data breach has occurred in Glasgow City Council - with information relating to social work and psychological reports having previously been lost - but the sheer scale of this loss is staggering.
"An investigation is now under way, and if the people of Glasgow are to have any confidence in their council's data security in future, they must fully explain how such a huge data loss could occur, and what steps will be taken to prevent this in future.
"As part of this, the council must explain why it seemingly took over a week for them to realise the extent of the data loss, and almost a further week for this to be made public."
People who read this story also read
- Rangers crisis: Possibility of selling Ibrox naming rights 'being explored'
- Brothers stabbed mother's partner after they thought he attacked her
- Man performed sex act on the fast lane of one of Scotland's busiest roads
- Missing Edinburgh woman with learning difficulties last seen in Glasgow
- Grandson of jailed paedophile carried out sex attacks on two schoolgirls