Renault may be facing a "catastrophe" if they're found to have broken the rules with their brake-balance system, says Ralf Schumacher.
It was revealed after the Japanese Grand Prix that Racing Point had lodged a protest against the cars of Daniel Ricciardo and Nico Hulkenberg over a "pre-set lap distance-dependent brake bias adjustment system".
Ricciardo and Hulkenberg climbed from 16th and 15th respectively on the Suzuka grid to finish sixth and 10th, moving Renault well clear of Racing Point and Toro Rosso in fifth place in the constructors' championship.
If Renault are found to have driven with the alleged devices, reports have suggested that punishments could be as serious as disqualification from the 2019 season standings – something a team has not been subjected to since 2007 and McLaren's 'Spygate' controversy.
Schumacher says the complaint would not have been lodged had Racing Point not built up significant evidence to support their case.
"The driver is normally responsible for adjusting the brake balance, so if it is happening automatically you could brake later and take more speed into each corner," Schumacher told Sky F1.
"It would be a big advantage. An automatic system controlled electronically could do it much better and faster than the driver can manually.
"The suspicion must be reasonable, because it's an unwritten rule that you don't accuse another team of something like that unless you're 100 per cent sure and if it's proven right, it's a catastrophe for Renault.
"The FIA already seems overwhelmed with the simplest decisions, and this is definitely a mammoth task.
"They need to be completely sure, because it would be a huge setback for Renault."