Jacques Villeneuve has accused organisers of the French ice-racing series Trophee Andros of attempting to "rig" the outcome.
After the grand final in Super Besse, the 1997 world champion accused the organisers of breaking their own rules to help Alain Prost, according to RMC.
The report said F1’s quadruple world champion Prost was allowed to have his car repaired after a crash.
"We realised we were not participating in the Andros trophy but the Alain Prost trophy," French Canadian Villeneuve said.
"I question my commitment because of that. This was not sport," he charged.