The suspension will come as a severe blow to the credibility of the commission, which is handling its first big inquiry since it was opened 18 months ago to replace investigations by police themselves.

The clerk, who could face serious charges, is alleged to have links with ITV news staff.

On Wednesday Sir Ian Blair, the Commissioner of the Metropolitan Police, privately asked Nick Hardwick, head of the IPCC, to call in an outside police force to investigate the leaking of papers which revealed a series of “catastrophic blunders” over the death of Jean Charles de Menezes.

Sir Ian yesterday rejected demands for him to resign. He said: “I’m not going to resign — I have a job to do.”

The suspension comes amid a growing dispute between the IPCC and Sir Ian, who is understood to want a “Hutton style” judicial inquiry into the case, like that conducted into the death of Dr David Kelly, the government scientist.

The leaked papers include statements from officers, a pathology report and photographs. No one had seen the material outside the IPCC and yesterday John Cummins, the senior investigator, was forced to brief lawyers for the family about the investigation.

The Yard is also at odds over claims that police tried to delay the IPCC taking over the case after Mr de Menezes died at Stockwell Underground station on July 22.

Yesterday the IPCC added further fuel to the row when John Wadham, the deputy head of the commission, said that police “initially resisted us taking on the investigation but we overcame that. This dispute has caused delay in us taking over the investigation but we have worked hard to recover the lost ground”.

Sir Ian replied that he raised the role of the IPCC because it would have to disclose information to the families of those affected and he questioned how this would work during a counter-terrorism operation.

Last night the Brazilian Government said that it would be conducting an inquiry into the shooting after news of blunders and erroneous reports deepened its anger. A Brazilian mission will visit Britain next week.

Kate Hoey, Mr de Menezes’s local Labour MP in Vauxhall, called on Sir Ian to make public what he knew about the shooting and when he knew it. “We need real answers and as quickly as possible,” she said. Gareth Peirce, one of the solicitors representing the family of Mr de Menezes, supported the idea of an inquiry. She said: “A public inquiry is the only kind of inquiry that can deal effectively with the big policy issues brought up in this case.”

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Time-worn Freddie gives up Test matches
• Brighton company 'involved in cyber attack'
• The art of survival: it's all in the mind