MONTREAL, Canada - Germany's Auto Bild newspaper has carried a report that the Red Bull Formula 1 team carried out pre-season indoor testing on a rolling road in Graz, Austria. The facility allows static vehicles to be run at high speeds on rollers; whether air was passed over the vehicle (to simulate a wind-tunnel test) was not known.The six-day test, involving Red Bull's troubled engine supplier Renault, reportedly occurred after the last pre-season track test in Bahrain (February 2014 ) and before the start of the 2014 Australian GP.'SPENDING WEEKEND IN GRAZ'Rumours of the illegal test reportedly began to circulate after an unnamed source circulated correspondence to the governing International Automobile Federation and to Mercedes, Ferrari and Sauber.Auto Bild reported that the test involved Red Bull's junior team Toro Rosso which had been deeply involved in efforts to pull Renault out of its pre-season technical crisis.Red Bull test driver Antonio Felix da Costa tweeted in March 2014 that he was headed to Austria for a "five-day trip".Da Costa said: "Spending the weekend in Graz, Austria. Not by choice though!"Stay with Wheels24 for the 2014 Canadian F1 GP weekend.