Lewis Hamilton could face a second penalty ahead of the Sao Paulo Grand Prix due to a possible technical infringement following qualifying, while Max Verstappen is also at risk of a sanction.

Hamilton has already taken a five-place grid penalty for Sunday's grand prix after receiving a new engine, although he is first set to get the opportunity to add points in the sprint race after qualifying fastest on Friday.

However, FIA technical delegate Jo Bauer discovered an issue with the Mercedes man's DRS that could deal a further blow to Hamilton's title hopes.

"The uppermost rear wing element adjustable positions were checked on car number 44 for compliance with Article 3.6.3 of the 2021 Formula One Technical Regulations," Bauer said in his report.

"The requirement for the minimum distance was fulfilled, but the requirements for the maximum of 85mm, when the DRS system is deployed and tested in accordance with TD/011-19, were not fulfilled."

#F1 - @LewisHamilton dominated qualifying for #BrazilGP by beating rival @Max33Verstappen to pole position for the #F1Sprint . @ValtteriBottas finished 3rd https://t.co/wgWAaK7EjE pic.twitter.com/Zwf6TnDmcT
— FIA (@fia) November 12, 2021

The rear wing assembly in question has been removed and impounded, and the issue has been referred to the stewards, who delayed a decision until Saturday after calling in a Mercedes representative late on Friday.

"The stewards have adjourned the hearing relating to Document 18 of the 2021 FIA Formula 1 Sao Paulo Grand Prix as they await further evidence," a spokesperson said.

The stewards have also called in Verstappen and a Red Bull representative over an "alleged breach of Article 2.5.1 of the FIA International Sporting Code", which states: "In the Parc Ferme, only the officials assigned may enter. No operation, checking, tuning or repair is allowed unless authorised by the same officials or by the applicable regulations."

Verstappen was seen approaching Hamilton's car in Parc Ferme and a fan video appeared to indicate he touched the rear wing.

Hamilton and Verstappen must now await the decisions of the stewards, which could prove significant in their pursuit of both victory in Brazil and the title.