Lewis Hamilton has hinted that Max Verstappen's tyre failure in Baku was down to the way Red Bull was running its tyres and not the fault of Formula One tyre supplier Pirelli.
Verstappen crashed out of the lead of the Azerbaijan Grand Prix two weeks ago after his left rear tyre exploded at over 200 mph with five laps of the race remaining.
Earlier in the race, Lance Stroll suffered a similar failure on his left-rear tyre and also crashed into the wall at high speed.
Pirelli's investigation into the failures found there was not a production or quality issue with the tyre while Red Bull claimed no car fault was found and the tyres were run to Pirelli's parameters "at all times".
Running lower tyre pressures tends to result in more performance from the tyre, but Pirelli sets a mandatory minimum tyre pressure ahead of each race to stop teams putting the integrity of the tyres at risk with very low pressures.
One theory behind the Baku failures is that Verstappen's tyre pressures met Pirelli's parameters when the tyres were put on the car, but did not raise with Pirelli's expectations as they warmed up while the car was on track.
Ahead of this weekend's French Grand Prix, the FIA announced that additional random tyre pressure checks would be introduced after each session to make sure teams are not running lower pressures while the car is on track.
"Wherever there is a failure, they [Pirelli] always put the pressures up, so that tells you something," Hamilton said in a press conference in France.
"More often than not the tyres are not running at the pressures that are being asked.
"We didn't have a problem with our tyres. I think they [Pirelli] have done a great job with the tyres this year, they're more robust than before.
"And in this particular instance, I don't think Pirelli are at fault."
In the same press conference, Verstappen said he was unhappy with Pirelli's explanation of the failure.
Hamilton said he was surprised the FIA needed to clarify the rules around tyre pressures ahead of the French Grand Prix but welcomed the move.
"I was very surprised, naturally, to see they had to clarify those... which obviously you can take what you want from that," Hamilton added.
"I'm happy that they have acknowledged that they need to clarify it, and I think what's really important from now is how they police it, as they've not been policing how the tyres are being used [while on track] -- tyre pressures, tyre temperatures, and we need to do better.
"It's great they've done a TD [technical directive], but it's the action now we need to see them follow through, and be really vigilant, to make sure it's equal across the field."