Briatore lost his job over the Singapore race-fix charge
A Renault employee, codenamed Witness X, has emerged as a key whistleblower in Formula 1's race-fixing scandal.
Renault were given a two-year suspended ban for ordering Nelson Piquet Jr to crash so that team-mate Fernando Alonso won the 2008 Singapore Grand Prix.
Ex-team boss Flavio Briatore was banned indefinitely and ex-engineering chief Pat Symonds excluded for five years.
It had been thought that Piquet, Briatore and Symonds were the only people who knew about the race fixing.
However, a fourth team member, who had not himself been a conspirator, was aware of the plan before the race but was opposed to it.
The FIA says in a report on its website that Witness X had told their investigators he had been "personally present at a meeting shortly after qualifying on Saturday 27 September 2008 when Mr Symonds had mentioned the possibility of a crash plan to Mr Briatore".
The report continued: "The FIA's advisers were confident Witness X himself played no active role in the conspiracy and that, indeed, he had objected to it and sought to distance himself from it."
The FIA was not made aware of the whistleblower until five days ago, when Renault provided additional documents.
And it was Renault's third and final set of written submissions on Saturday that sealed Briatore's fate.
Renault F1 added: "As a result of the evidence, including Mr Piquet's admission, Mr Symonds' responses and Witness X's evidence, Renault F1 concluded that they and Mr Briatore must have known about the conspiracy."
Meanwhile, Symonds has apologised for his role in the scandal that resulted in him being excluded from Formula 1 for five years.
"I would like to acknowledge my role in this incident," stated Symonds.
"I was the one who, when the idea was first suggested to me by Nelson Piquet Jr, should have dismissed it immediately.
"It is to my eternal regret and shame I did not do so. I can only say I did it out of a misguided devotion to my team and not for any personal gain whatsoever.
"I consider the role I have played in bringing the team to where it is today to be my life's work.
"In a single action I have destroyed the high reputation I have built up during a 33-year career in motor sport. On that night in Singapore last year I made a mistake the consequences of which I could never have imagined at the time.
"For that mistake I can only offer all of you, and all those touched by the action I was involved in, my profound apology."
Piquet Jr apologised for his role in the scandal but claimed: "I bitterly regret my actions to follow the orders I was given. I wish every day that I had not done it."
He was given immunity from individual sanctions in exchange for volunteering his evidence to the FIA.
Briatore and Symonds parted company with Renault last week at the same time as the French car giant said they would not contest the charges.