Race director Charlie Whiting reminded teams on Saturday morning that drivers will be penalised if they gain an advantage by cutting Spa's Turn 4, the left hander at the top of Eau Rouge.

A detection loop has been situated behind the kerb there, and it is triggered whenever a car runs with all four wheels off the track.

The system has been labelled the 'Cheat Loop' on the official F1 timing screens, with several drivers having been detected of running wide there in practice.

In updated notes sent to the teams and headlined "cutting behind the apex of turn 4" on Saturday, Whiting pointed out that any offenders in today's qualifying sessions would have those laptimes deleted.

In addition, anyone doing it more than three times in Sunday's race would result in a warning flag, with subsequent examples potentially leading to sanction.

Whiting wrote: "Any lap completed during qualifying by leaving the track and cutting behind the apex of turn 4, as judged by the detection loop in this location, will be deleted by the stewards.

"On the third occasion of a driver cutting behind the apex during the race he will be shown a black and white flag, any further cutting will then be reported to the stewards.

"Each time any car cuts behind the apex teams will be informed via the official messaging system."