The Corrupt Practices Investigation Bureau (CPIB) said yesterday that it is assisting French authorities who are looking into a Singapore-registered business suspected of receiving money to get support for Japan's 2020 Olympic bid.
British newspaper The Guardian reported on Wednesday that €1.3 million (S$2.02 million) was made in two payments to Black Tidings, a marketing consultancy owned by Ian Tan Tong Han and linked to Papa Massata Diack, son of disgraced former International Association of Athletics Federations (IAAF) president Lamine Diack.
French police reportedly uncovered this transaction, made in 2013, as part of their investigations into alleged fraud at the IAAF.
That same year, Tokyo won the right to host the Olympics, ahead of Madrid and Istanbul.
While Japan's Olympic chief Tsunekazu Takeda said yesterday that the payments were "legitimate", a CPIB spokesman said: "The Corrupt Practices Investigation Bureau is working with the French authorities on this case. As investigations are ongoing, we will not be able to comment further."
It did not say if any arrest has been made, but Diack junior is wanted by Interpol for alleged money laundering and corruption.
Besides the money from Japan, Black Tidings is also tied to extortion and bribery allegations involving the IAAF and is believed to be the crux of institutionalised corruption in the world athletics body.
Records from the Accounting and Corporate Regulatory Authority (Acra) showed that the company, known as Black Tidings Publishing until 2011, was registered in 2006 by Tan, who is 34 this year, and a Malaysian, Fong Mok Seong.
Fong withdrew as owner in 2011, leaving Tan the sole proprietor. The business was then terminated in 2014, a year after the payments.
Acra records also listed its focus as "advertising activities" and showed that the place of business was Tan's residential address, a flat in Dakota Crescent.
When The Straits Times visited the unit yesterday, no one answered the door, although footsteps from within could be heard.
A neighbour said he had not seen the owner for about two weeks, adding that the bespectacled man would often play with his children on the surrounding lawn.
Japanese media and a wire agency were also spotted staking out the place, hoping to catch a glimpse of the man in question.
According to The Guardian, Tan was also consultant to Athlete Management and Services, a Dentsu Sport subsidiary based in Switzerland, although Dentsu has since denied any involvement with Tan.
Singapore Athletics president Tang Weng Fei, who failed in his bid to become IAAF treasurer last year, claimed he had not heard of Ian Tan but said he met the "friendly" Diack junior a few years ago.
According to Asian Athletics Association (AAA) secretary-treasurer Maurice Nicholas, Tan had been involved in sponsorship work with the AAA.
Nicholas, who last saw Tan about five months ago, said: "He seemed like an honest and nice person. Our senior vice-president Du (Zhaocai) dealt with Tan's company.
"He helped us secure some sponsorship. I'm a bit surprised to hear about this."