Magic circle firm Allen & Overy has said it is ‘looking into’ the allegation made yesterday that it was tricked into handing over details relating to former prime minister Gordon Brown to a conman.

An article in today’s Guardian newspaper claims that that lawyers at Allen & Overy were tricked into handing over details from Brown’s file in 2000 by a conman allegedly working for the Sunday Times.

The newspaper claims Brown was targeted by News International journalists attempting to access his voicemail and obtain details of his bank account, legal file and medical records.

It reported that a tape recording shows Barry Beardall, who was subsequently jailed for fraud, calling the law firm claiming to be an accountant acting for a company interested in buying Brown’s flat.

Allen & Overy had acted for the administrators of the Maxwell group.

One of the assets the administrators had had to dispose of was a flat in London which Gordon Brown had bought.

A spokesman for Allen & Overy said the firm is looking into the matter.

He categorically denied that any personal details relating to Brown could have been handed over.

‘Gordon Brown is not and never has been a client of the firm. We do not have personal details in relation to him.

'We have not given out any of Gordon Brown’s personal legal files because we do not have any,’ he said.

The spokesman added: ‘It looks like there’s a possibility that someone called pretending to be someone they were not.’

The spokesman said the firm had heard a tape recording made at the time of the alleged incident, but said its quality was poor.

He said that as the recording related to events that happened some years ago, the firm needed to find out who the people mentioned in it were.

He added: ‘Nothing of a personal nature was handed over. It seems likely that it might have been details relating to the valuation of a property.’