Italian MotoGP great Valentino Rossi has accused reigning world champion Marc Marquez of "destroying" the sport by riding dangerously and without respect for his rivals.
The pair clashed on a damp track in Argentina on Sunday, with Rossi falling after being pushed onto the grass by the Spaniard, who had already incurred a ride-through penalty for a breach of start procedures.
Rossi finished 19th with Marquez, who was handed a 30-second penalty for the collision, also out of the points in 18th position.
"I'm OK, but this is a very bad situation," Rossi said of the incident with Marquez, who was refused access to the Yamaha garage in an attempt to apologise after the Italian dismissed the move as PR for the cameras.
"If you take what happened this weekend as an example, one incident can happen to anybody, you can make a mistake in braking, you can touch the other guy. It can happen, it's racing.
"But from Friday morning on, Marquez did this to (Maverick) Vinales, to (Andrea) Dovizioso, to me, and on Saturday morning, and today he went straight through four riders," added the 39-year-old nine-time world champion.
Rossi said such behaviour created a dangerous situation, which would only be made worse if others acted in the same way as Marquez, who has won four of the last five world championships.
He said he had spoken to race director Mike Webb and hoped his words had an effect.
"They have to do something," added Rossi. "I'm scared on the track when I'm with Marquez. I was scared today when I saw his name on the board.
"I'm not race direction - they will decide - but like this he is destroying our sport, because when you do 300-kilometre an hour on the track, you have to have respect for your rivals."
Marquez accepted in a Honda release that he had been to blame for a high-speed collision with compatriot Aleix Espargaro but said the Rossi clash was down to the conditions.
"I touched a wet patch, locked the front, and released the brakes. I tried to turn, again making my best effort to avoid contact. When he crashed I immediately apologised," said the Spaniard.
"It was a tricky Sunday. Of course today I made some mistakes, which I recognise."