A senior colleague of Met Police chief Sir Ian Blair has backed his account of the aftermath Brazilian Jean Charles de Menezes's fatal shooting by police.
Mr Menezes was shot the day after alleged bombing attempts
Sir Ian's claim he did not realise Mr Menezes was not a terrorist until the day after he died has been questioned.
But ex-Deputy Assistant Commissioner Alan Given told the Observer it took 24 hours to confirm his innocence.
Meanwhile, the Met Police has denied another newspaper story claiming Sir Ian was in line for a £34,000 bonus.
In a statement released following a story in the Sunday Telegraph, the Met Police said no decision would be made on bonuses until June this year.
The statement added: "Sir Ian Blair made it clear several months ago that he would neither seek nor accept a bonus this year."
Mr Menezes was shot and killed by armed officers from the Met's CO19 unit in Stockwell Tube Station on 22 July last year - one day after failed bomb attacks on the capital's transport network.
Mr Given, who was the most senior officer in charge of CO19 that day, made his comments following claims that Sir Ian's office misled an inquiry over the shooting's aftermath.
The pressure on the Met Police chief intensified this week after he admitted secretly recording conversations with the attorney general and the chairman of the Independent Police Complaints Commission.
Sir Ian also attracted criticism after he said he could not understand why the Soham murders had attracted such huge media coverage.
Mr Given, who has now retired, attended meetings with senior officers later on the day of the shooting.
There have been calls for Sir Ian to resign in recent weeks
"When I left, I had no indication that the wrong person had been shot - I did not learn the truth until the following day," he said.
Earlier in the day, Mr Given held talks with the officers who carried out the shooting.
"There wasn't even a sniff of the fact that there had been a tragic mistake," he said.
The meeting was sombre but the officer's mood was buoyant because they initially were convinced they had just shot a terrorist, he added.
"They had done the job that we ask firearms officers to do - to go out into potentially dangerous situations and shoot somebody."
He told the Observer he was speaking out due to a sense of injustice that his former boss was being undermined.
Another Deputy Assistant Commissioner, Brian Paddick, had claimed a close aide of Sir Ian thought police had made a mistake six hours after the Tube killing.
The Met responded that the claim was "simply not true" and Mr Paddick said that statement amounted to accusing him of lying.
The IPCC has completed its report into the shooting itself and submitted it to the Crown Prosecution Service.