Shoot-to-kill victim's mother arrives in Britain to be greeted by new claims about son's death

Giovani de Menezes, the victim's brother, said: "We want to know why it happened, what happened, and why the police didn't tell us the true facts."

He was speaking at Heathrow, where he arrived with his parents, Matozinhos Otone Da Silva and Maria Otone de Menezes, his wife and their three young children. Mr Menezes's mother said: "We are searching for justice. I want the police to be punished." His father repeated: "Justice, justice, justice."

Today, they will visit Stockwell Tube station in south London, where Mr Menezes was shot by officers who believed he was a suspected suicide bomber. The shooting came the day after the failed bomb attacks of 21 July.

The family's trip is being funded by the police, although they are being accompanied by their solicitors. Tomorrow, they will meet the Independent Police Complaints Commission (IPCC), which is investigating the shooting and may also meet Sir Ian Blair, the Metropolitan Police Commissioner, whose career depends on the inquiry's outcome. He has admitted considering resignation over the matter.

The issues being examined include the precise timing of when senior officers first knew their marksmen had shot an innocent man and whether and to what extent the news was kept from Sir Ian.

Reports yesterday claimed that, by 3pm on the day, five hours after the shooting, the Yard knew Mr Menezes was Brazilian and not linked to terrorism, although his precise identity had not been established.

Yet Sir Ian told a press conference at 3.45pm that day that the shooting was "directly linked to ongoing terrorist operations" . It was not until 10.30am the following day that Sir Ian was told of the error formally and it was not announced publicly until 5pm, after police had traced his relatives.

Other reports yesterday spoke of the "utter confusion" at Scotland Yard while surveillance officers tracked Mr Menezes from his flat in Tulse Hill and on the bus to Stockwell Tube station, which had been used by three of the bombers the previous day.

The block of flats was being watched because a suspect was believed to be linked to another flat in the block; the surveillance officer outside had asked colleagues to have a closer look at Mr Menezes because the officer was distracted by having to urinate behind a tree.

Because Mr Menezes behaved in such a way as to make officers believe he was using counter-surveillance techniques, armed officers from CO19 were summoned to arrest him. But they arrived too late to detain him outside the station and were forced to pursue him on to a train, where he was identified to them by a surveillance officer. He was shot seven times in the head and once in the shoulder under the Operation Kratos guidelines for dealing with suicide bombers, which stipulate that officers must aim for the head to prevent detonation of a bomb wrapped around the body.

The family are expected to get a full briefing on the progress of the inquiry - due to be completed by Christmas - when they meet IPCC officials tomorrow. The commission has promised that Mr Menezes' relatives will be the first to see much of the evidence it has uncovered about the shooting, although Nick Hardwick, the chairman, has said there will be some material that cannot be disclosed for reasons of national security and because it does not want to prejudice any future action.

Mr Hardwick condemned what he called the constant "drip-drip" of leaks to the media about the case. He said: "I am extremely concerned at recent reports in the press about this case and would urge everybody to stop."

n A man was arrested yesterday in connection with the attempted terror attacks on London on 21 July. The 36-year-old man was arrested by officers from the anti-terrorist branch on suspicion of assisting an offender and alleged immigration offences.

The unanswered questions

1. Why was a surveillance officer watching the front door to a whole block of flats - from which any number of people could emerge - and not the door of the suspect flat itself, which was not the one occupied by Jean Charles de Menezes?

2. Why was the officer forced to relieve himself behind a tree - at the precise moment Mr Menezes came out? He was therefore unable to get a proper look at him, and set off a chain of events by asking colleagues to check. Such officers normally would work from a van with a lavatory; it is not known why one was not deployed, but it is likely that the force's resources would have been severely stretched that morning.

3. Why did the armed officers fail to arrive at Stockwell Tube station and give Mr Menezes a chance to surrender outside? Were they summoned too late, or were they stationed too far away? Why, according to one report yesterday, did they waste time checking a bus outside when they ought to have been told he had already gone underground?

4. What passed between the officers on the ground and the commanding officer at Scotland Yard, Commander Cressida Dick? And who else was in operational command of the incident? Reports yesterday claimed there was confusion involving Commander Dick, Commander John McDowall, in charge of surveillance, and Assistant Commissioner Alan Brown, the head of the overall anti-terror operation.

5. Key questions are raised by the account of one surveillance officer, known as Hotel Three, on board the Tube train. According to leaks of his statement to the Independent Police Complaints Commission, he verbally indicated the suspect to the armed officers before grabbing Mr Menezes around his torso and pinning him to the seat. The armed officer then shot Mr Menezes before dragging his colleague away. His actions were in contravention of the Operation Kratos guidelines in dealing with suicide bombers, which state that officers should not approach them and shoot in the head to kill. Does that mean Hotel Three was unaware of them? Crucially, if he had the suspect under control, why did the firearms officers need to shoot?

6. Further questions have now arisen about events after the shooting. According to some reports, four senior officers told the Met's command group that they knew "within hours" that an innocent man had been shot. One suggestion was that this was only three-quarters of an hour before Sir Ian Blair said on television that the shooting was "directly linked to terrorism". He later said that it was not until 10.30 the following morning that he was formally told that a terrible mistake had been made. Why did it take so long? And if senior officers were sure by the same afternoon, why was Sir Ian not told and a public statement made? Or was he kept in the dark deliberately?