The International Automobile Federation (FIA) on Friday reprimanded the Mercedes Formula One race team and tyre makers Pirelli for carrying out unauthorised tests.

The tests, carried out over three days in May in Barcelona, followed protests from the Red Bull and Ferrari teams that they contravened Formula One race laws.

The much-anticipated decision followed a day of hearings in Paris on Thursday, held by the FIA’s international tribunal, where both Mercedes and Pirelli defended their actions, saying they had no intention of flouting the sport’s regulations.

The issue has badly divided Formula One with Mercedes on one side and world championship rivals Red Bull and Ferrari on the other – and the FIA had a range of sanctions at its disposal, including fines and suspensions.

But in what will be seen in some quarters as a let-off for both companies, motorsport’s ruling body settled for simple reprimands with Mercedes also suspended from participating in a coming three-day young driver training test to be held at Silverstone on July 17-19.

The tests were carried out by Mercedes drivers Lewis Hamilton and Nico Rosberg.