City police opposed an independent investigation into their fatal shooting of a Brazilian man they mistook for a suicide bomber, a British official said Thursday, as allegations grew of a cover-up.

"The Metropolitan Police Service initially resisted us taking on the investigation, but we overcame that," said John Wadham, chairman of the Independent Police Complaints Commission (search), which is now investigating the killing of Jean Charles de Menezes (search).

Police issued Wadham's statement after lawyers for the Menezes family met with the complaints commission, demanding more information about the killing.

Menezes, 27, was shot seven times in the head by police who tailed him to a south London subway station on July 22 — one day after four bombs were planted on the transit system by suspected terrorists. The bombs failed to detonate fully.

Two weeks earlier, bombs on three London trains and a double-decker bus killed 52 commuters, Western Europe's first reported suicide bombing.

The Guardian newspaper reported Thursday that Sir Ian Blair (search), director of London's Metropolitan Police, tried to block the commission's independent probe because it could have a negative affect on national security and intelligence. The paper also said police kept IPCC from the shooting scene for three days.

A commission spokeswoman declined to say if that delay was unusual, and the Home Office, which oversees British national security, refused to comment.

But Blair denied there was any cover-up.

"Those allegations, I have to say, do strike at the integrity of this office and the integrity of the Metropolitan Police, and I fundamentally reject them," he said in an interview with London's Evening Standard newspaper.

He acknowledged writing a letter to the Home Office, the Metropolitan Police Authority — the London police force watchdog — and the complaints commission saying he thought the terrorism investigation should take precedence over a probe into the Menezes killing. But he denied trying to block a probe.

On Tuesday and Wednesday, a British TV station leaked documents from the complaints commission investigation that contradicted police accounts of Menezes's death.

That prompted a Metropolitan Police Authority official to say the investigation must be made public.

"The leaks, apparently from the IPCC report, demonstrate that there are problems with the procedure. I therefore think it's time now to come clean and actually let us all know exactly what's been going on," Jenny Jones, a Green Party member of the police authority, said Thursday in an Associated Press interview.

"The Met has a fantastic reputation as a trustworthy police force whose officers often aren't even armed. But we have to find out what went wrong in this surveillance operation and whether the bad information we have received about it was an accident or a cover-up," Jones said.

On Thursday, lawyers for the Menezes family demanded answers.

"This has been a chaotic mess," said lawyer Gareth Peirce, who accused police of stalling the investigation. "One of the things we asked the IPCC to investigate is: Are there lies that have been told? Who told them?"

In central London, the public also criticized the probe.

"It's just outrageous. You can't go around shooting innocent people. Will this happen again?" said Ian Bennett, 22, an aerospace engineer. "It's really worrying if there has been a big cover-up attempt."

"They're supposed to be pillars of justice and honor," Victoria Shillito, 22, said of the London police. "Now? You just don't know. I'm shocked."

In the heightened state of anxiety after the July 7 suicide attacks and failed bombing two weeks later, witnesses reported that Menezes, who they claimed was dressed and acting suspiciously, leaped station ticket barriers before bolting from armed officers toward a train.

Blair eventually apologized for the killing. However, on July 22, he told journalists that Menezes failed to obey police instructions and officers said "his clothing and his behavior at the station added to suspicions."

But the leaked reports made by public by ITV News suggested inaccuracies in the initial police statements.

Brazil's Foreign Ministry said offidials plan to question police in England about the shooting, saying the new reports have "outraged" the government,

"The most recent news, accompanied by images with a strong visual impact ... heightens the sense of outrage of the Brazilian government," the ministry said in a statement on its Web site.

Officers trailed Menezes for more than a half-hour before the shooting, and no attempts were made to stop him, according to ITV. The surveillance officer who called in reports about Menezes described him as wearing a denim jacket and carrying nothing, but suggested he was "worth someone else having a look."

The Brazilian calmly entered the Stockwell subway station, paused to pick up a free newspaper and used his travel card to pass through the barriers, according to the ITV report citing documents apparently based on closed-circuit TV footage.

After descending the escalator and running to catch his train, Menezes took a seat. One of at least three surveillance officers who had followed him onto the train pointed him out to armed police.

The surveillance officer says he then "heard shouting which included the word 'police,'" ITV reported.

Menezes stood up and walked toward the surveillance officer, who tackled Menezes and pushed him back into the seat.

Then "I heard a gunshot very close to my ear and was dragged away on to the floor," the officer said.

A police spokesman told AP that officers have the authority to decide to shoot to kill if they believe their lives or those of the general public are at risk, especially regarding a suspected suicide bomber.