ALEX Salmond did not go to the police to complain about his bank account being hacked because he wanted to protect his informant, his spokesman has claimed.

Despite the First Minister revealing for the first time in his evidence to the Leveson Inquiry that his confidential financial records had allegedly been targeted by the Observer in 1999, the spokesman said Mr Salmond's current view was that it was the responsibility of the newspaper and not the police to investigate.

However, he said Mr Salmond "did not rule out the possibility" of referring the matter to the police in the future.

The spokesman confirmed that information that his bank account had been targeted was passed to Mr Salmond by a former Observer journalist in the early 2000s and he would respect the confidentiality of that source.

A former Observer journalist, Alex Bell, is head of policy, research and strategy in Mr Salmond's team of special advisers.

The spokesman said an obligation of reporting the incident to the police would mean having to disclose the informant's identity, and the First Minister believed "that at this point in time that's not necessary".

"What is necessary is that the newspaper looks more deeply into this," he added.

Despite a gap of at least a decade since Mr Salmond was told his banking arrangements had been targeted, the spokesman said he had only complained about it last year because no story had appeared at the time, but it had become relevant again because of the phone-hacking issue and the Leveson Inquiry.

Mr Salmond wrote to the editor of the Observer, John Mulholland, last July, saying: "It has been brought to my attention that there was a strong suggestion that journalists working for the Observer accessed my bank account details in 1999. Could you please let me know if there is any truth or substance in these claims?"

A spokeswoman for the Observer said that on the basis of the information supplied by Mr Salmond they had been unable to find any evidence to substantiate his allegation.

She added: "As our response to him at the time made clear, we take this allegation very seriously, and if he is able to provide us with any more information we will investigate further."

A Labour spokesman said: "If the First Minister has evidence his bank account details were illegally hacked into, we believe it is incumbent upon him to report the matter to the police.

"The First Minister has stated that the source of this information is a former Observer journalist. While we appreciate the First Minister's desire to preserve the anonymity of his source, as one of his most senior aides, Alex Bell, is also a former Observer journalist, it is likely that people will jump to possibly erroneous conclusions.

"In the interests of clarity we believe the First Minister should confirm that Mr Bell is not the source of these allegations."

Mr Salmond's spokesman said: "The First Minister was given the information in confidence, which he will respect, and therefore we will not indulge in a guessing game or a process of elimination on this matter."

Mr Salmond faced more questions about his relationship with the Murdoch empire at First Minister's Questions yesterday when Labour leader Johann Lamont branded him "Rupert Murdoch's lackey" and claimed he failed to ask the tycoon how many jobs a News Corporation takeover of BSkyB would have brought to Scotland.

Mr Salmond has said his interest in the proposed deal was that it would secure jobs.

He insisted the takeover would have been good for employment, citing evidence that Mr Murdoch's son, James, had given to the Leveson Inquiry when he said the deal would potentially lead to an increase in BSkyB's operations in Scotland.