Japan denied on Thursday allegations of a $1.5 million payment made during the winning bid for the 2020 Tokyo Olympic games, saying they had won it cleanly.

Britain’s The Guardian newspaper reported Wednesday that the Tokyo bid team “or those acting on their behalf” paid about 1.3 million euros ($1.5 million) to a Singapore bank account.

It said the account was linked to Papa Massata Diack, the son of disgraced former IAAF President Lamine Diack.

French prosecutors confirmed in March they had widened their probe into corruption at the IAAF to include Olympic bidding for the 2016 and 2020 Games.

Tokyo 2020 spokesperson Hikariko Ono said in a statement that the committee “has no means of knowing these allegations. We believe that the Games were awarded to Tokyo because the city presented the best bid.”

Japanese chief cabinet secretary Yoshihide Suga told a news conference that he was unaware of the newspaper report.

“I am confident that our bid was conducted in a clean manner,” Suga said, adding that should Tokyo be approached by French authorities on the matter, it would cooperate.

Japan, which won the right to host the games over Istanbul and Madrid in 2013, has been beset by a number of woes over the Games, including scrapping its original design for the centerpiece Olympic stadium, which has delayed construction.

Last month, it selected a new games logo after its previous one was withdrawn due to allegations of plagiarism.