The trial of Lamine Diack, a former head of athlectics chief begins today in Paris.
The trial had ben due to start in January but was postponed after new documents containing testimony from his son and co-defendant were submitted to the court.
The former president of the International Athletics Federation is standing trial on charges of corruption, money laundering and breach of trust linked to a Russian doping scandal.
Prosecutors allege he solicited 3.45 million euros from athletes suspected of doping to cover up the allegations and allow them to continue competing, including in the 2012 London Olympics.
Mr Diack, who turned 87 on Sunday, has denied wrongdoing. His lawyers have also said the accusations are baseless.
The former president led the governing IAAF, now renamed World Athletics, from 1999-2015 and was among the most influential men in the sport.
Mr Diack has been living under house arrest in Paris and faces a jail sentence of up to 10 years if convicted.