Paris: French investigators suspect that payments made to the son of disgraced athletics supremo Lamine Diack to get support for Tokyo's 2020 Olympics bid, a source close to the inquiry said yesterday.

Some 1.3 million euros ($1.5 million) paid to a company owned by Papa Missata Diack is at the centre of the suspicions. Diack father and son face corruption charges in France. The Japanese government insisted earlier that the Tokyo bid was "clean".