Ferrari's Sebastian Vettel has been summoned by stewards at the United States Grand Prix over an alleged breach of regulations during the first practice session.
The session was halted in order for officials to sweep the Turn 9/10 area of gravel, after Sauber's Charles Leclerc went wide and dragged stones onto the circuit as he recovered from his moment.
Vettel has been summoned for a allegedly failing to slow sufficiently during that red flag period.
Should Vettel be found guilty then a grid penalty is likely to be issued, with Daniel Ricciardo and Esteban Ocon both having received three-place demotions for a similar transgression earlier in the year.
