A Brazilian businessman gave $2m to the son of Lamine Diack, the now disgraced former IAAF president and at the time also an IOC member, just three days before Rio won the right to host the 2016 Olympics, the French newspaper Le Monde has claimed.

Citing sources among French investigators, Le Monde said it had established concrete information that Pamodzi Consulting, a company founded by Papa Massata Diack, received a $1.5m payment from a holding company based in the British Virgin Islands. Diack Jr, at the time a marketing executive for the IAAF, received $500,000 from the same company, which was transferred to a bank account in Russia.

The International Olympic Committee has launched an investigation into the revelations and into further allegations against Frankie Fredericks, the former Namibian sprinter who is now an IOC member and head of the 2024 Olympics evaluation commission. Fredericks denies any wrongdoing. “The IOC remains fully committed to clarifying this situation, working in cooperation with the [French] prosecutor,” the organisation said.

According to the paper, French investigators believe the money may have been used to influence the election for the 2016 Olympics, which was held in Copenhagen in 2009. It said that French investigators had established the holding company is linked to a Brazilian businessman who specialises in subcontracting. It also alleged that the businessman had been involved with many construction deals with the state of Rio, related to the Olympic Games.

Diack Jr, who was banned from athletics for life last year and is currently on the run from Interpol, told the paper: “Good luck for your article!” when asked for his response.

Last year, the Guardian revealed how the Tokyo Olympic bid team made a €1.3m payment to the Black Tidings secret bank account in Singapore, which is linked to Diack Jr, during Japan’s successful race to host the 2020 Games. Diack Jr was also apparently involved in 2008 in a scheme to deliver “parcels” to six influential members of the IOC at a time when Doha, Qatar, was trying to bid for the 2016 Olympics.

Diack Sr, who is currently in custody in France facing charges of money laundering and corruption, refused to comment on the story. However the Rio 2016 spokesman Mário Andrada told Le Monde: “The elections were clean. Rio won by 66 votes against 32, it was a clear victory.”

Le Monde also said that Diack Jr had transferred $299,300 via Pamodzi Sports Consulting to the offshore company Yemli Limited on 2 October 2009 – and that Yemli Limited was linked to Fredericks, who was an International Olympic Committee scrutineer at the vote in Copenhagen.

Fredericks told Le Monde that the payment had “nothing to do with the Olympic Games”. He said: “I had the idea to develop a relay championships. In addition I supported the IAAF marketing programme, the African athletics programme, the IAAF Continental Programme and the African athletics championships. My attendance at various events and promotional efforts are documented and accordingly these services can be substantiated by other evidence.

“Payment was in respect of services rendered in the period 2007 to 2011. The payment has nothing whatsoever to do with the Olympic games. By the way, I was not an IAAF board member at the time, but an IAAF ambassador, and did not breach any regulation or rule of ethics.”

When asked why it was he had been paid in 2009, precisely on the day of the election day for the 2016 Olympics, he replied: “Despite the contract being concluded in 2007 I had not been paid, and therefore started to put pressure on Pamodzi Sports Consulting, and this culminated in the payment in 2009.”