Marc Marquez has been given a penalty point for his part in a clash with Dani Pedrosa’s at last month’s Aragon Grand Prix.
Repsol Honda has also lost the 25 points he won at Alcaniz and now lead Yamaha by a single point in the constructors’ championship.
The Spaniard’s arm brushed team-mate Pedrosa’s machine, severing a rear wheel speed sensor cable that disabled his compatriot’s traction control, causing him to flip off the front of the bike.
"I would like to know where is the limit in racing because I also can ride aggressively and over the limit," Pedrosa told BBC Sport after the Aragon race.
Marquez is one more point away from starting his next race at the back of the grid, having accrued two points already this season at Silverstone.
That could cause havoc to his title hopes as the rookie is currently 39 points ahead of second placed Jorge Lorenzo, and only has to finish second or better in the last four races regardless of Lorenzo’s efforts.
"We are sending a message to Marc,” said Race Director Mike Webb on the Moto GP official website.
"We have had an incident in which Marc has been very close to another rider - close enough to make contact - when coming from behind under braking.
“For us, that is a signal [even though the contact itself was quite minor] to make a formal warning by way of a penalty point to Marc to say he has to take more care."
Marquez leads the championship on 278 points from Lorenzo’s 239, with Dani Pedrosa a further 20 points back on 219.