Hembery explains blank Pirelli tyres in Barcelona 2 March, 2012 Pirelli tyre being washed in Barcelona Mar.2 (GMM) Tongues were wagging in the Barcelona Formula 1 paddock on Thursday when some drivers hit the Spanish circuit using unmarked Pirelli tyres. Some of the tyres, the compounds of which are normally visibly differentiated with coloured branding, featured significantly different markings. The big rumour was that, now just two weeks before the start of the season in Australia, teams had requested the blank tyres in order to hide their test programmes from their rivals. According to France’s Auto Plus, motor sport director Paul Hembery cleared up the matter by explaining that the blank tyres were in fact “prototypes”. They had been manufactured not at Pirelli’s usual F1 factory in Turkey, but elsewhere, in the event that a natural disaster forced the tyre supplier to change its plans at the last minute. Hembery also answered the criticism that, after Pirelli’s initial 2011 tyres spiced up the racing early last year, the new generation might not be aggressive enough. “We need data from the races to judge that,” he insisted. “It’s far too early.” He also confirmed that Pirelli is close to announcing the identity of its 2010-specification test car, and a new test driver. It is believed that former Force India driver Adrian Sutil is a candidate. Subbed by AJN Tweet Related NewsVettel first Ferrari test not breach of contractYas Marina Test Day 1: Bottas tops as McLaren Honda flopsRed Bull play hardball block Vettel’s Ferrari testMcLaren-Honda aiming for Abu Dhabi testRed Bull confirm Sainz for Abu Dhabi testF3 champion Ocon impresses Ferrari in F1 testDTM champion Wittmann awarded Toro Rosso testFong and Nissany to test a Sauber in ValenciaF3 champion Ocon to test for LotusMcLaren planning private Honda tests?