The publisher of the Daily Mail newspaper has said a laptop containing the financial and personal details of thousands of staff and suppliers has been stolen, according to reports.
Details such as names, addresses, bank account numbers and sort codes were on the laptop, which was password protected, the Guardian newspaper reported.
In a letter to those who details were affected, Simon Dyson, finance director at Daily Mail publisher Associated Newspapers, and Martyn Hindley, his counterpart at sister company Northcliffe, said it was likely that the details had been erased by the thief.
"The likelihood is that this theft was carried out in an opportunistic manner by a thief who will not realise that there is any personal data on the laptop and who may just erase what is on the hard disk in order to disguise the fact that the laptop is stolen."
They blamed a "technical issue" and said they had "already strengthened" security procedures.
"We have, of course, notified the police of the theft of the laptop and are talking to the Office of the Information Commissioner about what has happened," they said.