The FIA has moved to close new loopholes in the technical regulations.
Auto Motor und Sport says the implication of the seven new technical directives issued before Paul Ricard is that teams were exploiting the existing rules.
One involves the rear wing, specifying the way the main plane should be bolted to the endplates. The implication is that some teams’ wings were overly flexing.
"Ferrari thinks Mercedes used this trick, while at Mercedes they are convinced of the opposite," said correspondent Michael Schmidt.
Another directive relates to the engine and exhaust, stopping teams from blowing air onto mini-wings on the rear crash structure for aerodynamic effect.
It is believed two teams have asked for a two-race delay in the implementation of the directive in order to rewrite engine software.
"Ferrari should be one of the teams," Schmidt added.