Mercedes’ George Russell was disqualified from the Belgian GP after his race victory following a stewards investigation into his underweight car.

Russell’s car was weighed after the race and found to be at the minimum weight (798 kilograms), but after fuel was drained from the Mercedes, it was found to be 1.5kg underweight.

The matter was referred to the stewards, who determined Russell’s car be disqualified.

“Car 63 was weighed on the FIA inside and outside scales with both scales showing the same result of 796.5kg,” a stewards’ statement said. “The calibration of both scales was confirmed and witnessed by the competitor.

“During the hearing the team representative confirmed that the measurement is correct and that all required procedures were performed correctly. The team also acknowledged that there were no mitigating circumstances and that it was a genuine error by the team.

“The stewards determine that Article 4.1 of the FIA Formula One Technical Regulations has been breached and therefore the standard penalty for such an infringement needs to be applied.

“Competitors are reminded that they have the right to appeal certain decisions of the stewards, in accordance with Article 15 of the FIA International Sporting Code and Chapter 4 of the FIA Judicial and Disciplinary Rules, within the applicable time limits.”

Russell won the race on a one-stop strategy, meaning he made a single set of tyres last 34 laps while others made an extra stop.

The physical wear of the four tyres can account for the car’s overall weight loss over a long stint, although teams usually factor that into their calculations before the race.

Another factor unique to the Belgian Grand Prix is that the length of the Spa-Francorchamps lap means drivers do not complete a cool-down lap after the chequered lap and instead turn into the pit lane exit immediately after Turn 1.

The absence of a cool-down lap means drivers cannot pick up discarded rubber on their tyres, which is standard procedure after a race to help replace any lost weight.

“Heartbreaking. … We left it all on the track today and I take pride in crossing the line first,” Russell said in a post on social media after the race. “There will be more to come.”

Speaking before the stewards’ decision, Mercedes team principal Toto Wolff said his team would have to accept a disqualification if it happens.

“You have to take it on the chin,” he said. “If the stewards decide against ourselves, it is what it is, a mistake has happened, or could have happened, and one-two would have been a great result going into the summer break. It wouldn’t go any better.

“The positive, the very positive we can take from this race is we had two cars that were the benchmark in this race, with two different strategies. Who would have said that a few months ago? That is really good to see.”

Asked if anything was damaged on Russell’s car, which might have contributed to it being underweight, Wolff added: “No, I think it’s a one-stop that … you expect loss of rubber, maybe more, but it’s no excuse.

“If … if the stewards deem it to be a breach of regulations, then it is what it is, and we have to learn from that, and as a team, given there are more positives to take, for George, but that’s a massive blow for a driver when his childhood dream is winning these races, then to be told it’s taken away. But he’s going to win many more.”