A former governor of Rio de Janeiro says he helped pay a $2m (£1.6m) bribe to secure the Olympic Games for the Brazilian city in 2016.
Sérgio Cabral told a judge the payment was made to secure votes in the decision-making meeting in 2009.
He said that Carlos Nuzman, then the chairman of the Brazilian Olympic Committee, handled the negotiations.
In 2017, Mr Nuzman was arrested amid an investigation into the alleged vote-buying scheme. He denied wrongdoing.
Cabral is currently serving a 200-year sentence for several corruption cases.
On Thursday, he said the then-president of the International Association of Athletics Federations (IAAF), Senegal’s Lamine Diack, also served as intermediary in the alleged deal.
Mr Diack is to stand trial in France, having been arrested there in 2015. He has been accused of taking payments for deferring sanctions against Russian drugs cheats. He has previously denied wrongdoing, but not responded to the latest allegations.
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Both Mr Diack and Mr Nuzman were suspended from their roles and later resigned.
Cabral also said Brazil’s then-president, Luiz Inácio Lula da Silva, had been informed after the money had allegedly changed hands.
Lula’s lawyers have said this is untrue. Lula has been jailed in a separate corruption case.
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Cabral, who served two terms as Rio state governor from 2007 to 2014, has been jailed in connection with a corruption case involving the construction company that built the Rio Games.
Several high-powered Brazilian executives and politicians have recently reduced their sentences through plea bargains and giving evidence against others.
The International Olympics Commission (IOC) says its chief ethics officer is following up on the latest allegations, adding that the IOC members mentioned in Cabral’s testimony had been contacted.
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Cabral told investigators that his bribe had been aimed at winning the support of nine of the committee’s 95 members.
The IOC implemented a series of reforms in 2014. On Friday, it said: “The IOC is fully committed to address any issues, including those which happened before the far-reaching reforms.”
Rio won its Olympic bid in 2009, beating co-finalists Chicago, Madrid and Tokyo. It was the first South American city ever to host the Games.