Sauber`s Charles Leclerc sounded off at Haas rival Kevin Magnussen after the pair collided at the Japanese Grand Prix on Sunday.
"Magnussen is and will always be stupid. It`s a fact," the future Ferrari driver declared over the team radio after the coming together on the second lap as Leclerc was poised to overtake.
Television replays showed the Sauber hit the rear of the Haas after the Dane moved to the right to defend on the main straight.
The incident, which brought out the safety car after Magnussen left debris on the track as he struggled back to the pits with a puncture and damaged car, was deemed a racing incident. Both drivers later retired.
"I`ve only done one year in Formula One and for sure the driver which I had the most problems with is definitely Kevin," said Leclerc. "And I`m not the only one, as I`ve obviously spoken with other drivers. So I don`t really understand why sometimes we aren`t a bit more harsh with drivers like this because otherwise, we are going to continue like this."
Haas team boss Guenther Steiner defended his driver, however, and said Magnussen had moved over before the braking point.
"He (Leclerc) ran into him," he said. "Kevin didn`t brake. He didn`t push him off or anything, Kevin just moved over to his line and he ran into him. What can he do? Just let him by?"