"No," the Briton said. "We have promised him immunity if he cooperates," Mosley added, referring to the Brazilian driver's sworn statement to the FIA about the Singapore GP crash affair.
"We did the same thing two years ago with Alonso in the espionage case," he said.
The same immunity has not been granted to Alonso, the winner of the event last September, this time around, but Mosley said there is no evidence the Spaniard was a part of the conspiracy.
Asked to compare this scandal with 'spy-gate', Mosley explained: "The problem with McLaren was that they were not telling the truth. But purely regarding what Renault is accused of, this (the crash accusation) is perhaps worse."
Evidence that has been leaking into the media in the past days does not bode well for Renault's chances at the 21 September hearing, but Mosley said the French team must for now be given the benefit of the doubt.
"We do not have enough evidence in hand because we have not heard the story from the perspective of Renault," said the FIA president. "There are always two sides to a coin and we have to respect that."
Mosley admitted that telemetry data in the FIA's possession seems to indicate that Piquet caused the crash deliberately, but he warned that part of Renault's defense might be "numerous similar cases" in which a driver has legitimately lost control in the same way.
Meanwhile, he has bad news for Nico Rosberg, who had hoped that a retrospective disqualification for Alonso would make him a debut GP winner.
"We cannot change the outcome of the race," said Mosley, explaining that after November 30 last year, the 2008 world championship results were set in stone.