Lewis Hamilton is set to receive a five-place grid penalty at the Austrian Grand Prix, as a result of an unscheduled gearbox change.
An FIA document, issued on Friday evening, confirmed that the gearbox inside Hamilton's W08 has been changed ahead of this weekend's race at the Red Bull Ring.
Drivers must use the same gearbox for six consecutive events, aside from if they retire, but Mercedes has been forced to change Hamilton's gearbox before the end of his current run.
Technical Delegate Jo Bauer has referred the matter to Austrian Grand Prix stewards, with the five-place grid drop a formality.
The document also revealed that Mercedes informed Bauer of the change on Tuesday morning, meaning Hamilton entered the weekend with prior knowledge of his impending sanction.
"The above driver did finish the last race in Baku and this gearbox change was before the six consecutive events expired," said the note.
"As this is not in compliance with Article 23.5a of the 2017 Formula One Sporting Regulations, I am referring this matter to the stewards for their consideration. The team informed the technical delegate about the gearbox change on Tuesday, 04th July 2017, at 11:29 hours."
Hamilton, who has been quickest in both practice sessions this weekend so far, currently trails Sebastian Vettel in the standings by 14 points.