Met Police 'gagged' Leveson Inquiry from addressing claims officer leaked information to News of the World

The Leveson Inquiry was under fire tonight after claims Scotland Yard gagged it over extraordinary allegations against a senior officer.

Fresh questions emerged about its effectiveness as it emerged a report detailing suspicions that the officer was leaking to the News of the World was withheld.

The London force claimed a 'public interest immunity certificate' to ban the disclosure of paperwork accusing the officer of obtaining confidential information.

Hearings: When Lord Justice Leveson published his report he criticised the Met for errors in its handling of the phone-hacking scandal

It is not clear whether the bid was successful, but the document was withheld anyway until after its contents could have been useful in public hearings.

Tonight Met Commissioner Sir Bernard Hogan-Howe faced calls to 'urgently review' the extraordinary development.

Labour MP Tom Watson said the claims of a cover-up were 'remarkably serious' as the disclosure prompted a furious war of words.

He said: 'As the Prime Minster has said, this inquiry was supposed to have left no stone unturned but it now appears to have been gagged by the very force it was set up to investigate.

  More... Butcher who was Tasered by police after brandishing two knives outside Buckingham Palace is spared jail Doctors take pregnant woman, 37, with 'severe mental disorder' to High Court to STOP her having an abortion From tennis pals at Oxford to the very top of Government: How Lord Feldman has been at Cameron's side for decades

'I'm sure the current Commissioner would wish to urgently review what happened and I will be writing to the Home Secretary Theresa May to ask that she satisfies herself that all seemingly vital documents from the Yard were not withheld from Lord Justice Leveson.'

At the centre of the row is a Met intelligence report from 2006 which accuses a former senior officer of leaking for cash.

The information allegedly passed on to the now-defunct Sunday tabloid supposedly related to the stewardship of the then Commissioner Lord Blair.

Scotland Yard is accused of withholding the document from the Leveson Inquiry until after those involved could have been questioned on its contents in public.

Claims: Scotland Yard is accused of withholding the document from the Leveson Inquiry until after those involved could have been questioned on its contents in public

In a statement, Robert Jay QC, counsel to the inquiry, confirmed that Scotland Yard had claimed 'public interest immunity' in relation to the internal intelligence report.

Asked why he did not question senior officers about it, he replied that the inquiry was not shown the police report until April 23 last year.

'As the Prime Minster has said, this inquiry was supposed to have left no stone unturned but it now appears to have been gagged by the very force it was set up to investigate'

Labour MP Tom Watson

This was seven weeks after a raft of police officers including Lord Stevens, Lord Blair and Sir Paul Stephenson were quizzed.

Mr Jay, who is poised to become a High Court judge, said the inquiry had a continuing 'obligations of confidence' to the police in relation to their submissions.

He added: 'These factors have at all stages limited what I am able to place in the public domain, and continue to do so.'

The inquiry into press ethics started in November 2011 and held evidence-gathering hearings for nine months.

An entire section was devoted to examining the relationship between the press and the police after a series of scandals.

When Lord Justice Leveson published his report he criticised the Met for errors in its handling of the phone-hacking scandal.

Comments: In a statement, Robert Jay QC, counsel to the inquiry, confirmed that Scotland Yard had claimed 'public interest immunity' in relation to the internal intelligence report

He also accused it of fostering a 'perception' that some senior officers were too close to News International.

Since the inquiry effectively exonerated Scotland Yard, police across the country have launched a crackdown on the media.

Dozens of journalists have been arrested, as have police officers and other public servants accused of leaking information, even when no money changed hands.

'The contents of this intelligence report, if true, are disturbing'

Bob Quick, Scotland Yard's former head of counter-terrorism operations

Bob Quick, Scotland Yard's former head of counter-terrorism operations, said he was 'surprised' the report was not examined during the inquiry.

He told the Evening Standard: 'The contents of this intelligence report, if true, are disturbing.

'When it was discovered, it was swiftly and properly handed over to the Met prior to the Leveson hearings and I am surprised its content was not subject of some examination during the inquiry.'

A Met spokesman said: 'The intelligence report referred to dates from 2006. It did not identify an individual as the source of information allegedly being disclosed from the Met management board and it was not considered that it warranted further action.

'Intelligence reports may contain sensitive information and this document was therefore shared with the inquiry on a confidential basis.

'The Met will neither confirm nor deny whether Public Interest Immunity was sought in relation to any material provided to the inquiry. It was not for the Met to determine what was or was not put to any witnesses or used as evidence.'