The Mercedes team is under investigation following first practice for the British Grand Prix after an alleged breach of the sporting rules.
A report by the stewards said Mercedes had covered Nico Rosberg's car after the German had to stop early in the session because of a hydraulics problem.
As the car had suffered no damage, FIA technical delegate Jo Bauer said covering the underside of the car was considered a breach of article 27.4 of the rules.
The rule states: "During the entire Event, no screen, cover or other obstruction which in any way obscures any part of a car will be allowed at any time in the paddock, garages, pit lane or grid, unless it is clear any such covers are needed solely for mechanical reasons, which could, for example, include protecting against fire."
The incident has been referred to the stewards and the team is scheduled to meet with them at 1pm.
"During P1 at 10:28 members of the Mercedes AMG Petronas F1 Team covered the underside, rear diffuser area and the front wing of car number 06 when it was brought back to the paddock after it having stopped on the circuit due to a mechanical problem," said Bauer.
"As the car hasn't suffered any kind of accident damage this in my opinion is a breach of Article 27.4 of the 2015 Formula One Sporting Regulations and I am referring this matter to the stewards for their consideration."
Rosberg was quickest in the session.