Lewis Hamilton secured his sixth win of the season with an impressive drive to victory at Sunday's Italian GP, widening the gap between him and title challenger Sebastian Vettel to 30 points in the drivers’ championship.

However, moments after the conclusion of the race, attention quickly shifted elsewhere when Romain Grosjean was told he had actually been disqualified despite initially finishing sixth.

The Frenchman had managed secure to a points finish for the fourth consecutive race.

But it has been taken away from him following a protest from Renault regarding the floor of Grosjean's Haas.

FIA technical delegates examined Grosjean’s car in parc ferme and race director Charlie Whiting stated that concerns were raised regarding ‘a small detail on the leading edge of the floor’ of the Haas car.

On the back of a lengthy investigation, an official statement was released which read ‘the reference plane of car number 08 is found not to be in compliance’ with neither the regulations nor a subsequent technical directive issued in July, which teams had to comply with by Monza.

FIA further explained the scenario and defended their verdict saying that ‘the text of this Article was being applied differently by several different teams' and that a technical directive clarifying the issues was issued to all teams on July 25 ahead of the Hungarian GP.

Teams were given a deadline until the Italian GP to comply with the clarification.

Haas contacted FIA’s technical chief Nikolas Tombazis to assure him that they would introduce the changes from the upcoming Singapore GP and requested some flexibility in this matter at the present situation.

Tombazis informed the American outfit’s aerodynamics chief he understood the issues in relation to the supply problem but if they didn’t make a correction by Monza, other teams were bound to lodge a complaint with the officials.

In response, Haas have confirmed they are planning to appeal the decision.

Guenther Steiner said: "We do not agree with the Stewards' decision to penalize our race team and we feel strongly that our sixth-place finish in the Italian Grand Prix should stand. We are appealing the Stewards' decision.”

As a result of the disqualification, Renault [86 points] retake fourth place in the championship while Haas drop back to 76 points.

Meanwhile, Force India move ahead of Toro Rosso to seventh on 32 points, with Grosjean slipping to 14th in the drivers’ championship.