When the safety car came out to control the field while debris from the accident was cleared, Alonso was alone among the front runners in not having to stop for fuel and tyres and therefore in a position from which he was able to win.
Renault's internal investigation found that team boss Flavio Briatore, engineering director Pat Symonds and Piquet Jr had conspired to cause the crash with no other team member involved.
After opting not to contest the FIA's charges, Renault parted company with Briatore and Symonds and the pair have since been banned from FIA-sanctioned events - the former indefinitely and the latter for five years.
"I am relieved that the FIA investigation has now been concluded," said Piquet Jr, who was granted immunity from individual sanctions in exchange for volunteering his evidence to the FIA.
"Those now running the Renault F1 team took the decision, as I did, that it is better that the truth be known and to accept the consequences.
"The most positive thing to come from bringing this to the attention of the FIA is that nothing like it will ever happen again.
"I don't know how far my explanation will go to making people understand because for many being a racing driver is an amazing privilege, as it was for me."
In a statement released following a World Motor Sport Council hearing in Paris, Piquet Jr launched a stinging attack on Briatore, who was also his former manager.
"My situation at Renault turned into a nightmare," said Piquet Jr. "Having dreamed of being a Formula 1 driver and having worked so hard to get there, I found myself at the mercy of Mr Briatore.
"His true character, which had previously only been known to those he had treated like this in the past, is now known.
"Mr Briatore had my future in his hands but he cared nothing for it. By the time of the Singapore GP he had isolated me and driven me to the lowest point I had ever reached in my life.
"Now that I am out of that situation I cannot believe that I agreed to the plan, but when it was put to me I felt that I was in no position to refuse."
Piquet Jr, whose best finish in 28 races was second at the 2008 German Grand Prix, outlined his desire to return to Formula 1 and rebuild his career.
"I have had to learn some very difficult lessons over the last 12 months and reconsider what is valuable in life," said the son of three-time world champion Nelson Piquet.
"What has not changed is my love for Formula 1 and hunger to race again. I realise that I have to start my career from zero.
By the time of the Singapore GP Mr Briatoree had isolated me and driven me to the lowest point I had ever reached in my life
Nelson Piquet Jr
"I can only hope that a team will recognise how badly I was stifled at Renault and give me an opportunity to show what I promised in my career in F3 and GP2.
"What can be assured is that there will be no driver in Formula 1 as determined as me to prove himself.
"I do not expect this to be forgiven or forgotten but at least now people can draw their conclusions based upon what really happened."
BBC F1 analyst Martin Brundle felt the punishment handed to Renault might have been more severe and was heavily critical of Piquet Jr's decision to participate in the conspiracy.
"The FIA has been a bit more lenient on Renault than I thought they would be," Brundle told BBC Radio 5 Live.
"Renault have somehow satisfied themselves and managed to distance their parent company from the actions of their team personnel.
"I am massively unimpressed by Piquet Jnr and so are many others inside the paddock. He could have said no. He didn't need to do it. He's a man and can be responsible for his own actions.
"He didn't deliver at Renault as he wasn't fast enough and that's why he was released.
"The people who asked him to crash a car have been heavily punished with their reputations and creditably damaged and they are out of the sport. Piquet Jr gets off scot free and I don't think that's right."
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