Prior to the start of the race, the FIA found that Ferrari was in breach of regulations after the team declared a fuel measurement to the FIA that did not match the FIA's readings.
The FIA's technical delegate Jo Bauer described it as a "significant difference" and therefore reported the matter to the stewards, who heard from the team post-race.
The stewards confirmed that there was a 4.88kgs difference in the measurement that Ferrari declared, and the mass gathered by the FIA.
As a result, the stewards opted to issue Ferrari with a fine due to the inaccurate information but chose not to punish, who holds onto his 10th podium finish of the season.
"The Stewards heard from the team representative, FIA Technical Delegate and the FIA Head of Single Seater Technical Matters," read a stewards report.
"TD/014-19 required teams to declare the amount of fuel that they intended to put in the car for the laps to the grid, the formation lap, the race, the in-lap and any fire-ups that would be needed.
"The Technical Delegate was able to confirm the fuel mass put in the tank by checking in accordance with the procedure specified in TD/014-19. There was a difference of 4.88kgs between the team’s declaration for car 16 and the Technical Delegate’s measured fuel mass.
"The team’s declaration was therefore inaccurate and constituted a breach of the Technical Directive. This in turn constitutes an infringement of Article 12.1.1.i of the International Sporting Code.
"Accordingly, the stewards determined that the team should be fined €50,000 for its inaccurate declaration."
Bahrain International Circuit - Winter testing