The evidence against Renault in Formula 1's highly damaging 'Singapore-gate' race-fixing scandal is mounting up, after the R?gie's executive director of engineering Pat Symonds refused to deny that the team had instructed Nelsinho Piquet to crash on lap 14 of the top flight's inaugural night race in the Far-Eastern city-state just under a year ago.

The interview between Symonds and investigators for governing body the FIA took place over the weekend of the Belgian Grand Prix at Spa-Francorchamps at the end of last month. In it, the Englishman neglected to answer key questions surrounding the circumstances that saw Piquet collide heavily with the Marina Bay street circuit's concrete wall, ripping two wheels off his car and prompting a safety car period that vaulted then Renault team-mate Fernando Alonso from outside the top ten into the race lead, from where the double F1 World Champion would never look back en route to victory - a success that some believe was pivotal to convincing the French manufacturer to remain in the sport.

The principal issue upon which Symonds declined to comment centred around whether or not a meeting took place before the grand prix in the office of Renault F1 managing director Flavio Briatore in which Piquet was instructed to deliberately crash, and notified by the team's executive director of engineering of the precise point on the circuit at which he should do so to produce the best effect.

'Had there been no substance to the allegations made by [Piquet] and put to Mr. Symonds, it would have been straightforward for Mr. Symonds to deny them,' read a leaked report from the stewards to the FIA, published by The Times. According to the transcript obtained by the British newspaper, the meeting went as follows:

Investigator: "What do you recall being said to Nelson Piquet Jr at that meeting? This is shortly before the race."

Symonds: "I don't really remember."
Investigator: "You don't really remember?"
Symonds: "No."
Investigator: "Nelson Piquet Jr says he was asked by you to cause a deliberate crash. Is that true?"

Symonds: "Nelson spoke to me the day before and suggested that. That's all I'd really like to say."

Investigator: "Mr. Symonds, are you aware that there was going to be a crash on lap 14?"
Symonds: "I don't want to answer that question."

Investigator: "Mr. Piquet Jr says, having had the initial meeting with you and Flavio Briatore, you then met with him individually with the map of the circuit. Do you remember that?"

Symonds: "I won't answer. Rather not answer that. I don't recall it, but it sounds like Nelson's talked a lot more about it."

Investigator: "Mr. Piquet Jr also says that at that meeting, you pointed out a specific place on the circuit where he was to have the accident and said it was because it was the furthest away from any of the safety or lifting equipment, and gave the most likely chance of a safety car being deployed."

Symonds: "I don't...I don't want to answer that question."

Symonds went on to acknowledge that he, Piquet and Briatore had all played a part in the discussions that took place - but stopped short of admitting that he had personally asked the Brazilian to have an accident. Renault continues to refute all of the allegations, with the FIA's World Motor Sport Council (WMSC) due to meet in Paris on Monday (21 September) to deliberate over the team's fate.