By Chris Summers BBC News

Was Mr Menezes (left) mistaken for Hussain Osman?

The 21 July plotters failed to kill on the scale they had planned, but there was one person who unwittingly paid with his life in the wake of their attacks.

Jean Charles de Menezes was gunned down by police officers hunting for Hussain Osman.

Osman's lawyer, Anthony Jennings QC, said during his trial that officers had mistaken the Brazilian electrician for his client, who had tried to blow up a Tube train at Shepherd's Bush.

Chasing a lead

Mr Menezes, 27, was shot seven times in the head as he boarded a train at Stockwell Tube station in south London.

What is apparently not in doubt is that police were chasing up a lead from the rucksack Osman had abandoned in the train at Shepherd's Bush.

In it they found a gym club membership card that gave an address in Scotia Road, Tulse Hill, south London.

Are you aware police followed a young Brazilian from Scotia Road and shot him dead at Stockwell Tube station? The police believed the man they had killed was Hussain Osman Anthony Jennings QC

Mr Menezes was seen leaving an address in Scotia Road and was tailed by armed officers.

He boarded a number two bus for the 15-minute journey to Stockwell Tube station while members of the security services tried to confirm if he was the man they were after.

It is at the Tube station that events become less clear.

During Osman's trial at Woolwich Crown Court, Mr Jennings asked Det Con Dominic Murphy, who was one of the officers who later searched Osman's flat in Stockwell, about the shooting.

Mr Jennings said: "Are you aware police followed a young Brazilian from Scotia Road and shot him dead at Stockwell Tube station? The police believed the man they had killed was Hussain Osman."

Det Con Murphy replied: "I had no involvement in that operation."

I was very scared, I thought they would have shot me dead. I realised that this thing had taken a wrong turn and now an innocent man had been shot Yassin Omar

The trial also heard that when Osman's accomplices heard a man had been killed at Stockwell, they instinctively assumed it was Osman himself.

After hearing of the shooting, Yassin Omar fled to Birmingham disguised in a burka.

He said: "I was very scared, I thought they would have shot me dead. I realised that this thing had taken a wrong turn and now an innocent man had been shot."

Osman told the trial he had thought it was Omar who had been killed and had decided to flee the country because he had been terrified of being shot dead by police.

The Metropolitan Police has been accused of breaching its duty to non-employees but has denied a single charge - under the Health and Safety at Work Act 1974. The force faces a trial at the Old Bailey later this year.

The parents of Jean Charles de Menezes have criticised the police

In May this year the Independent Police Complaints Commission (IPCC) ruled that 11 officers involved in the Menezes shooting should not face disciplinary action. Decisions have yet to be made on the four most senior officers involved.

The IPCC has also been asked to investigate a complaint by the Menezes family that false statements were made by the Met to the media in the wake of the shooting, which implied that Mr Menezes had been acting suspiciously.

The Menezes family has reserved their heaviest criticism for the police and have said very little about any indirect responsibility Osman and the three other bombers bear.

Their solicitor, Harriet Wistrich, said she had no comment but added they were keenly anticipating the pending report from the IPCC.