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

George Russell was stripped of his victory at the Belgian Grand Prix after his Mercedes car was found to be underweight after the chequered flag.

Teammate Lewis Hamilton was promoted to first place, securing his second victory of the season after his win at the British Grand Prix earlier this month.

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