No-one will face charges over the alleged leak of papers from the Jean Charles de Menezes shooting probe.
Mr Menezes was killed after being mistaken for a suicide bomber
Police say no further action will be taken against three people arrested over the alleged Independent Police Complaints Commission leak to ITV News.
Lana Vandenberghe, who said she was one of the three, told ITV News her motivation had been exposing "a lie".
Mr Menezes was shot dead by police in London in July after being mistaken for a suspected suicide Tube bomber.
The alleged leak cast doubt on some of the circumstances of the Brazilian's death and led to claims of a cover-up.
It also prompted his family to demand the resignation of Metropolitan Police Commissioner Sir Ian Blair.
Ms Vandenberghe, a former secretary at the IPCC, told ITV: "He wasn't a terrorist at all, he was just a normal guy, wearing normal jeans and a jacket, going to work.
"And when I saw the videos, then I saw the state after he was shot, my heart ... I just thought, 'oh my God, this could be my daughter'."
She continued: "I knew from what I read and from what I learnt that it was a lie, and it appalled me that the police or the Met were not coming to light and saying we were wrong, this was a mistake."
The alleged leak was investigated by Leicestershire Police following a request from Scotland Yard.
In a statement, the force said it would not be charging a 43-year-old woman - Ms Vandenberghe - arrested on 21 September.
And no charges would be brought against a 30-year-old woman and a 29-year-old man arrested in October.
The force said the decision had been taken in consultation with the Crown Prosecution Service.
Mr Menezes, a 27-year-old electrician, was shot seven times in the head by anti-terrorist police at Stockwell Tube station the day after the alleged failed 21 July bomb attacks.
However, the documents obtained by ITV News appeared to suggest Mr Menezes had done little to arouse suspicion before he was shot dead other than emerge from a flat that had been under surveillance.
An eyewitness had said Mr Menezes had vaulted a ticket barrier and run down an escalator to escape firearms officers - claims which the Met failed to dispel.
The IPPC documents said he had walked into the station at a normal pace, even pausing to pick up a free newspaper.
They also contradicted claims he had been wearing a bulky coat, saying he was in fact clad only in a light denim jacket.
The documents prompted the Brazilian's family to make an official complaint to the IPCC, alleging they had been misled by Sir Ian.
That became the subject of a second official inquiry, which is due to conclude soon.
The first investigation report is now with the CPS, which is deciding whether any police officers should face criminal charges over the shooting.
The IPCC has reviewed its security following the alleged leak.