A council is investigating a report that a computer containing the personal details of thousands of its taxpayers was discovered on eBay.
Names and addresses, bank account numbers and sort codes of people in the Charnwood Borough Council area were reportedly found after the equipment was sold on the auction website for £6.99.
A spokeswoman for the Leicestershire authority said: "We can confirm that we are urgently investigating this report."
It is claimed other personal details, including conversations about householders' divorces and family bereavements, were also on the computer's hard drive.
The apparent security breach emerged a day after it was revealed that a computer storing information on up to one million bank customers was sold on eBay for £35.
Commenting on the latest revelation, the unnamed Scottish computer expert who bought the computer told the Daily Mail: "I can see from these documents who is having financial problems, and who is getting bailiffs sent round to their house.
"There is even information about a death on there. I was stunned to find 35,000 items - documents, photos, memos."
An investigation was launched on Tuesday after IT manager Andrew Chapman bought a computer on eBay, not knowing that the hard drive contained personal information relating to bank customers.
The computer was reportedly sold by an employee of data processing company Mail Source which is part of Graphic Data, a company that holds financial information for organisations. The equipment was used at the firm's archive centre in Shoeburyness, Essex.
Information including bank account numbers, phone numbers, mothers' maiden names and signatures of customers of American Express, NatWest and the Royal Bank of Scotland (RBS) were reportedly found on the computer.
