Met spent £5,000 on Yates's legal bill without authorisation

Scotland yard has been accused of spending more than £5,000 without authorisation on legal advice from a high-profile libel firm for one of its top police officers to enable him to pursue a defamation complaint, The Independent can reveal.

The Yard paid a total of £7,175 earlier this year to enable former assistant commissioner John Yates to hire the law firm Carter Ruck after a national newspaper published an article that he believed questioned his integrity with regard to the investigation of the News of the World phone-hacking scandal. Mr Yates resigned in July amid criticism of his conduct.

The Metropolitan Police Authority (MPA), which must authorise any spending by the Yard on external lawyers to defend the reputation of a serving officer, confirmed yesterday that it had set a cap of £1,500 on that expenditure.

Police sources said they believed the additional funding had been authorised, but the MPA has demanded an "urgent investigation" after its chairman, Kit Malthouse, was forced to apologise to MPs for providing incorrect information about the amount spent on legal fees. He also had to write to the Commons Home Affairs Select Committee to correct the figure.

An MPA source said Mr Malthouse was "not best pleased" at the disclosure of the additional spending.

Mr Malthouse said: "I have asked for an urgent inquiry as to why my decision to cap that expenditure was not adhered to."

The alleged unauthorised overspend came to light during the new Met Commissioner Bernard Hogan Howe's first appearance before the MPA last week. In response to a question from Liberal Democrat authority member Dee Doocey, Mr Hogan Howe said that in addition to a previously disclosed payment to Carter Ruck of £1,175 in March this year, the Yard had paid out a further £6,000 the following month. Carter Ruck, which has a reputation for aggressively pursuing its clients' defamation claims, sent letters to newspapers on behalf of Mr Yates after a story in The Guardian and other outlets about his decision in 2009 not to reopen the Yard's investigation into the hacking affair.

Mr Yates won an apology from the London Evening Standard for a story which suggested that he decided not to review the original investigation because he was afraid the News of the World would expose an alleged affair. But Mr Yates had separated from his wife and was openly in a new relationship. The Independent understands that the cost of the legal action against the Standard was not met by the MPA or the Yard.

In a statement, Scotland Yard said: "Funding for defamation work is available in exceptional cases where national publicity involves a major slur against the MPS as a whole, as opposed to an individual. It was felt that this case met that level and funding was approved.

"The request for payment was submitted in good faith.

"We will provide our fullest support to the MPA to help them find out exactly how the issue of the 'cap' was communicated."