McLaren ran into another rules controversy in the build-up to this weekend's Italian Grand Prix, when Formula One's stewards decided to fine the team for wrongly using a development gearbox in the Hungarian Grand Prix.

Already prevented from scoring points at the Budapest race following the qualifying antics of drivers Lewis Hamilton and Fernando Alonso, the Woking team - which continues to lead the world championship - was slapped with a $50,000 fine for using a new lightweight gearbox that had not passed a mandatory crash test.

The stewards revealed that, although McLaren had informed race director Charlie Whiting of the plan to use the 'box on the Thursday before the Hungarian race - and believed that the modifications made to the original were not major enough to warrant a crash test, the sport's governing body thought otherwise. After hearing from engineering director Paddy Lowe and team manager Dave Ryan on the eve of this weekend's Italian Grand Prix at Monza, they decided that rules had been broken and issued the fine

The stewards also implied that, had the plan to introduce the new gearbox been made known earlier, sufficient tests could have been arranged before the Budapest race, and noted that the team had used its original unit in Turkey while the development was crash tested. Results from that test have retrospectively satisfied claims that the gearbox was legal when it ran in Hungary.

The appeal hearing into the Budapest qualifying row is due to be heard on 19 September.