In an interview with NBC News, France's National Financial Prosecutor's Office head Jean-François Bohnert claimed "some very interesting people" were involved as investigations continue into the Olympics and other global sports events.

It is reported that another law enforcement source claimed "corruption in some form must exist in every major sporting event".

"Our place is to trace and track when corruption is at stake," Bohnert told NBC News.

"We see some mechanism of corruption.

"When there is some vacuum space, some very interesting people come into that field in order to make their unlawful activities."

Lamine and Papa Massata Diack are at the centre of a corruption probe relating to the bid process for Tokyo 2020. 

It was reported consultancy firm Black Tidings transferred $370,000 (£288,000/€313,000) to Papa Massata Diack around the time the Japanese capital was awarded the Games. 

Lamine Diack appeared in front of a French judge earlier this week as part of the investigation. 

Payments worth $2 million (£1.5 million/€1.7 million) made to Singapore-based Black Tidings, linked to Papa Massata Diack, are also the subject of investigations by French authorities in relation to alleged vote buying in connection with the 2020 Olympic and Paralympic bid race.

The payments were made before Tokyo was awarded the 2020 Games at the International Olympic Committee (IOC) Session in Buenos Aires in 2013.

Lamine Diack was a member of the IOC during the time of the 2013 Session and was viewed as having considerable influence over African IOC members.

Papa Massata Diack told Kyodo News that the money received was related to a "sponsorship deal made in China".

"There is nothing to do with the Tokyo Olympics," he said.

Both of the Diacks deny wrongdoing.

Former Japanese Olympic Committee (JOC) President Tsunekazu Takeda, chair of the Tokyo 2020 Bid Committee, is also being investigated over allegedly authorising the payments to Black Tidings.

Takeda, who denies wrongdoing, resigned as JOC President and as a member of the IOC last year after he was implicated in the scandal.

Earlier this month, Lamine Diack was found guilty of corruption by the Paris Criminal Court following an investigation into cover-ups of Russian doping cases for cash, and sentenced to two years in prison.

The cover-up of cases allowed athletes from the country to compete at major events including the 2012 Olympic Games in London and the 2013 World Championships in Moscow.

It is unlikely that the 87-year-old will spend any time in prison after the judge told him he could "expect conditional release" due to his age.

Papa Massata, who refuses to be extradited from Senegal, was also convicted and jailed for five years in absentia.

Tokyo 2020 is now set to take place in 2021 as a result of the coronavirus pandemic.