Lewis Hamilton and Max Verstappen are under investigation for potential rule-breaking in Mexican Grand Prix qualifying.
And several other drivers are also under the microscope after a farcical start to the session. Q1 was marred by several incidents as traffic played a major role in the first part of qualifying on a relatively short track.
On such incident saw several drivers block their rivals at the end of the pit lane. Verstappen was one of them and was placed under investigation by the stewards, who will look at his case after the session.
George Russell was also accused of the same thing as TV cameras showed him stationary at the end of the pit lane while others waited impatiently behind him. The Brit is also being probed by the stewards.
Those cars that were held up needed to hot-foot it to the line in order to start their final runs on time. But they were hampered further still when Fernando Alonso lost control of his Aston Martin and span around.
Sebastian Vettel warns of looming F1 ban and is "very worried about the future"That brought out the yellow flags which meant drivers had to slow in the first sector and could not use DRS. That effectively meant no-one was going to be able to improve in the final part of the session.
But some drivers were accused of flouting yellow flag rules. That included Hamilton who was investigated by the stewards for failing to slow down enough during that first sector of the track.
Logan Sargeant is another driver potentially facing a penalty after the session as the American is probed for both failing to slow under the yellow flags and is also accused of overtaking while they were flying.
Yuki Tsunoda is also involved in that probe as he was the one who was passed by the Williams driver. But Sargeant was the slowest qualifier anyway with only Tsunoda set to be behind him on the grid after accepting penalties for taking new engine components.
Lando Norris was the biggest casualty of Q1. He was not in hot water with the stewards, but his McLaren team took a strategy risk which did not pay off as he went out on mediums for the first lap. And, on his second and third runs on the softs, he made mistakes which led to him aborting the lap and going only 19th fastest.