Formula One boss Bernie Ecclestone has been questioned by state prosecutors in Munich, Germany, as part of an investigation into irregular payments made during the sale of the sport\'s commercial rights. Ecclestone, 80, was quizzed on April 6 as part of the investigation into payments worth 38 million euros ($50m) made to a German banker during F1\'s commercial rights sale five years ago, reports the Sueddeutsche Zeitung in Saturday\'s edition. Ecclestone\'s questioning came after the arrest in January of Gerhard Gribkowsky, the boss of Bavarian bank BayernLB, which had a stake in F1 up until to 2006. British billionaire Ecclestone, the CEO and president of F1\'s governing body, has said that he will continue to cooperate fully with the German prosecutors.