Bernie Ecclestone has dominated Formula One motor racing for forty years and made billions from the sport. But two courts say he paid a $44m bribe, a judge recently concluded that it was 'impossible to regard him as a reliable or truthful witness', and he may have avoided a billion pounds of UK tax. Panorama's Darragh Macintyre investigates the truth about the boss of F1, Bernie Ecclestone, and asks why he is still in charge.