A jailed banker has told a court in Germany that Formula 1 boss Bernie Ecclestone gave him a 50 million dollar bribe to facilitate a business deal.
Gerhard Gribkowsky, already convicted of taking the money, was allegedly paid to ensure that a company favoured by Mr Ecclestone could buy a stake in F1.
Mr Ecclestone denies bribery, claiming that he was a victim of blackmail.
If found guilty, the F1 boss could face a 10-year jail term and the end of his decades-long dominance of motor racing.
Prosecutors allege that by securing the sale of the stake to a company Mr Ecclestone favoured, he would remain in charge of Formula 1 and its commercial rights, broadcast payments and sponsorship deals.
Mr Ecclestone has argued that the payment was hush money, handed over because Gribkowsky had threatened to make false claims about the F1 boss's tax status.
Mr Ecclestone has run the sport for almost 40 years, turning it into a huge global commercial success.