Fresh questions have been raised over London Mayor Boris Johnson's dismissal of the phone-hacking scandal as "codswallop" last September after it emerged that his deputy had been told about the new police investigation.
Kit Malthouse, the deputy mayor for policing, has given conflicting accounts in the past week about what he was told by John Yates, the former Metropolitan Police assistant commissioner investigating new allegations raised by the New York Times in August 2010.
The newspaper's most serious claim was that the prime minister's media chief Andy Coulson knew about and approved of phone hacking when he was the editor of the News of the World (NoW).
Mr Malthouse, head of the Metropolitan Police Authority (MPA), said last week that he had received no specific briefings on phone hacking and had no discussions with senior officers about it in September.
An MPA spokesman also told BBC London on Friday that there had been "no specific briefings for Kit Malthouse on phone hacking".
But now Mr Malthouse has said that on 10 September Mr Yates told him that the investigation had been re-opened and former News of the World journalists were likely to be interviewed.
Labour and Green Party MPA members have said it is "inconceivable" the mayor would not have known this when he dismissed the allegations on 15 September.
Deputy mayor questioned
Mr Johnson said the claims were a "politically-motivated" attack on Mr Coulson and News International and insisted there was "nothing new".
The police inquiry ran for a few more weeks after that comment and a day before the mayor's remarks, detectives had interviewed Sean Hoare, a former News of the World reporter, after he told the New York Times (NYT) about Mr Coulson's alleged role in the scandal.
Mr Malthouse will face questions from members of the MPA on Thursday.
Mr Malthouse admitted his contact with Mr Yates in a letter to Green Party MPA member Jenny Jones on Monday, who had asked him for a full account of what he knew and when.
In the letter, he said: "I did not receive a specific face-to-face briefing on the NYT allegations in September.
"However looking in more detail at my diary yesterday I did find that John Yates' office had requested a telephone call.
"As I recall John rang me to reassure me that he was looking at the report in the NYT and considering whether there was any new evidence therein and approaching the newspaper to see if they could provide further evidence to substantiate their claims and that a team from the Met may fly to the USA to conduct interviews."
Mr Yates also wrote to the prime minister's chief of staff Ed Llewellyn on 10 September - the same day as his conversation with Mr Malthouse - offering to "brief" David Cameron on the latest phone-hacking inquiry, but Mr Llewellyn declined the offer.
Ms Jones said: "It seems inconceivable that the mayor was not told that the Met Police were taking the New York Times article seriously and were planning to interview the journalists involved.
"If the mayor was told, then he knowingly misled the public, pre-judged an active investigation and may well have influenced the police's willingness to pursue that investigation."
Joanne McCartney, Labour member of the MPA, said: "This raises further questions about what the mayor knew, when he knew it and why he took the stance he did."
Earlier this month, Mr Johnson said there had been one or two "brief allusions" during briefings largely focused on counter-terrorism.
Last week, Mr Malthouse said there had been "numerous" police updates over the past two years.
When asked about specific briefings, the mayor's office referred journalists to a letter written by Mr Yates to the mayor shortly before his resignation in which he said Mr Johnson had often "sought assurances" from him about the phone-hacking investigation.
The mayor's office has also refused to say whether he or his officials had discussions with the prime minister or his aides about phone hacking last September.
The Prime Minister's Office and the Home Office have also declined to say whether such discussions took place.