The Independent Police Complaints Commission, which is investigating the controversial killing of Jean Charles de Menezes, refused to confirm or deny the new information - broadcast by ITV News on Tuesday evening - which contradicted earlier police and eyewitness statements.
Police shot the electrician, 27, at point-blank range after he boarded a subway train on 22 July, one day after four suspected would-be bombers tried to attack London in a botched re-run of the 7 July bombings.
Initial reports said de Menezes had been acting suspiciously - wearing a bulky jacket, jumping a ticket barrier at Stockwell Underground station, south London, and sprinting on to the subway train - prior to his death.
But witness accounts and photographs leaked to ITV painted a different picture, showing the young man in a light denim jacket, walking calmly into the station. They revealed that de Menezes was restrained by a police officer on the train before being shot eight times.
In addition, a police officer outside his flat said he failed to videotape de Menezes when the Brazilian left home.
The revelations prompted relatives and campaigners to call for a public inquiry into the shooting.
De Menezes (2nd R) was shot at
point blank range
"My family deserves the full truth about his murder. The truth cannot be hidden any longer. It has to be made public," said de Menezes's cousin Allessandro Pereira.
The Justice4Jean Family campaign said people had been deliberately misled, adding, "We must ensure that the full lessons of this death are learnt by the authorities so that no other innocent Londoner suffers a similar fate."
The ITV report indicated the operation was flawed from the start as police monitored de Menezes' block of flats in Tulse Hill, south London, where they believed two suspects in the 21 July attacks were living.
The undercover officer outside, who was supposed to identify anyone exiting the building, admitted he had been away from his post when the Brazilian left.
"I was in the process of relieving myself," he was quoted as saying in documents obtained by ITV News.
"At this time I was not able to transmit my observations and switch on the video camera at the same time. There is therefore no video footage of this male," he said.
Closed circuit television footage later captured the electrician entering the station at a normal walking pace, even collecting a free newspaper, and slowly descending on an escalator, according to ITV News.
Contrary to dramatic witness accounts on the day, de Menezes is seen to board the train through the middle doors before pausing, looking left and right, then sitting down in either the second or third seat facing the platform.
"There's obviously some level of incompetence here or some serious breakdown in communications with the various officers involved in surveillance"
de Menezes family lawyer
Moments later, police burst in and apparently restrain the Brazilian before firing seven bullets into his head and one into his shoulder. Three more bullets missed him, and the casings were left on the floor.
A member of the police surveillance team was quoted as saying: "I heard shouting, which included the word 'police', and turned to face the male in the denim jacket.
"He immediately stood up and advanced towards me and the CO19 (special security) officers ... I grabbed the male in the denim jacket by wrapping both my arms around his torso, pinning his arms to his side.
"I then pushed him back on to the seat where he had been previously sitting ... I then heard a gun shot very close to my left ear and was dragged away onto the floor of the carriage."
Harriet Wistrich, a lawyer for the de Menezes family, said the new details further vindicated the electrician.
"There's obviously some level of incompetence here or some serious breakdown in communications with the various officers involved in surveillance," Wistrich told Channel Four News.