The Frenchman's Fiesta, which finished second in Leon on Sunday, was looked at in post-event scrutineering with a query raised over the gearbox.

Motorsport.com understands the gearbox could be underweight.

While the events from the third round of the world championship have been declared final, a footnote on the document reads: "Subject to further checks to be carried out by the FIA on the gearbox of car No 1."

Nobody from M-Sport was available for comment on the subject.

The FIA has confirmed to Motorsport.com that the gearbox has been sealed and will be taken from M-Sport to Geneva, where FIA technical Jerome Toquet will inspect it further.

Toquet will then make a report to the stewards from last week's Rally Mexico, and then a decision will be made.

The decision is expected to be known before the start of the next round of the championship, next month's Tour of Corsica.

One source told Motorsport.com: "Jerome will be looking at tolerances, he might well look at other gearboxes as well.

"This decision to investigate further infers there wasn't enough time to really get to the bottom it at post-event or it could mean there was a very strong defence from the team and that defence required further investigation.

"In terms of penalties if the car is found in contravention of the regulations, it could be anything from a time penalty to exclusion."

Underweight components have featured previously in the WRC, with Ford having all of its Focus WRC's hit by a five-minute penalty for running windows which were 0.5mm too thin.

Richard Burns' Peugeot 206 WRC was excluded from the 2002 Rally Argentina when the car's flywheel was found 20 grammes underweight.

If Ogier's car does contravene the regulations and he is excluded, he would lose his eight-point lead of the series and slip to third in the standings behind Jari-Matti Latvala and his teammate Ott Tanak.