BMW Sauber and Williams are under investigation of the Brazilian Grand Prix race stewards, autosport.com has learned.
Representatives of both teams were summoned to the stewards' office after their cars failed post-race inspection at Brazil.
The problem is believed to be in the temperature of the fuel samples taken from the cars of Williams's Nico Rosberg and BMW Sauber's Robert Kubica and Nick Heidfeld.
The trio finished the race in fourth, fifth and sixth respectively.
More details to follow...