MONTREAL, June 10, 2013 (AFP) - Mercedes and Pirelli chiefs will have to explain themselves to the International Automobile Federation's (FIA) International Court on June 20 in Paris over a private test carried out in Barcelona last month.
Mercedes' rivals Red Bull complained to FIA bosses about the tests once they came to light ahead of the Monaco Grand Prix just over two weeks ago.
The FIA announced the date of the hearing on Monday, the day after the Canadian Grand Prix in Montreal.
The International Court will announce its' decision a day after the hearing.
Responding to a request from Pirelli, Mercedes spent three days testing new tyres in Barcelona from May 15-17 in the week after the Spanish Grand Prix at the same venue.
Pirelli were proposing to introduce those tyres next season.
Red Bull Team Principal Christian Horner claimed that test was a "clear breach" of the rules and that Pirelli had approached his own team but they declined to take part in the test because "we felt it wasn't in line with the regulations."
He added: "I think the lack of transparency has been disappointing."
However, Mercedes counterpart Ross Brawn insists there was nothing underhand in his team's comportment.
"There has been an unfortunate branding of this being a secret test, but it was a private test," he said.
"To do three days in Barcelona - and 1000km of running - and to think that people would not become aware of it is naive. It was a private test not a secret one."
He added: "Sporting integrity is important to us, important to Mercedes and, when the facts become apparent, people can make a better judgement of the situation."
The International Court is a 12-member commission that has never sat before.
They could hand down a punishment of a fine, a points deduction or a ban from future Grand Prix races.