London's police commissioner came under criticism Thursday for reportedly stalling an investigation into the fatal shooting of a Brazilian man mistaken for a bomber.

Lawyers representing the family of Jean Charles de Menezes (search) also faulted police for not correcting false information made public that suggested the Brazilian had acted suspiciously before being shot seven times in the head by undercover police.

Menezes, 27, was shot by police who tailed him to the station the day after four bombs were carried onto London's transit system but failed to detonate fully. Two weeks earlier, 52 commuters had been killed by bombs on London trains and a bus.

"This has been a chaotic mess," said lawyer Gareth Peirce after meeting with the Independent Police Complaints Commission, which is investigating the shooting. Peirce is one of the attorneys representing the Menezes family.

"What we have asked the IPCC to find out is how much is incompetence, negligence or gross negligence and how much of it is something sinister."

In the heightened state of anxiety following the failed attacks, witnesses reported that Menezes, who they claimed was dressed and acting suspiciously, jumped over station ticket barriers before bolting from armed officers toward a train. Police also said that he failed to obey their instructions.

But a leaked report made by public by Britain's ITV television Tuesday into Menezes' death suggested the initial police statements about what happened that day were riddled with inaccuracies.

According to the leaked reports citing closed circuit TV footage, Menezes was trailed by officers for more than a half-hour before the shooting, and no attempts were made to stop him. The surveillance officer who called in reports about Menezes described him as wearing a denim jacket and carrying nothing.

The Brazilian calmly entered the Stockwell tube station (search), paused to pick up a free newspaper and used his travel card to pass through the barriers.

After descending the escalator and running to catch his train, Menezes was pointed out to armed police by one of at least three surveillance offices who had followed him onto the train.

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 the to the floor," the officer said.

While London Police Commissioner Sir Ian Blair (search) initially insisted Menezes was linked to the terror investigation, it soon become clear that he had no connections to the failed attacks and police expressed their deep regret at the shooting.

Peirce claimed that authorities tried to intervene and delay the investigation into how Menezes had become a victim of the new shoot-to-kill policy.

"We know not whether it was the commissioner of the Metropolitan Police or the home secretary, or both, (who) delayed their (the IPCC's) advent into the case. We have asked for a fast investigation on behalf of the family," Peirce said Thursday.

The Metropolitan Police confirmed that Blair did write to the head of the independent investigation group on the day of the shooting while police still believed Menezes was a suspected bomber.

Blair wanted "to clarify the role of the IPCC ... this was because it was crucial that the terrorist investigation took precedence over any IPCC investigation at that time."

The complaints commission said that by Friday evening, it had officially announced that it would take over the investigation into Menezes' death, and its officers began investigating the following Monday. A spokeswoman for the IPCC refused to say if this three-day delay was unusual.

The Home Office refused to comment.

Police said Menezes had attracted police attention because he left a building that was under surveillance because police believed one of the July 21 attackers, Hamdi Isaac, also known as Osman Hussein, lived there.

Officers tailing him concluded that he matched the description, according to the leaked documents cited by ITV. However, a surveillance officer had failed to record Menezes leaving the property in Tulse Hill because he had gone to the toilet and so was unable to switch on the video recording device, ITV said.

Police have refused to given any details, saying the material could feature in a court case