Tokyo-2020 Summer Olympics
IOC President Jacques Rogge announced Tokyo as the city to host the 2020 Summer Olympics during a ceremony in Buenos Aires, Sept. 2013. Reuters

A Japanese official who led the successful bid for the Tokyo 2020 Olympics said on Wednesday the Japanese Olympic Committee (JOC) plans to investigate the bidding after questions were raised about payments by the bid committee.

Media has reported the bid team made payments totaling more than $2 million to a Singapore bank account linked to Papa Massata Diack, son of disgraced former international athletics chief Lamine Diack.

Japanese officials have said the payments were legitimate consultant's fees.

Tsunekazu Takeda, president of the JOC and leader of the successful effort to win the Summer Games, said people involved with the bid would be questioned.

"We are setting up an investigative team that includes outside lawyers," Takeda told a parliamentary committee.

"We will once again talk with people connected to the bid at the time to ascertain whether or not there was anything illegal in the suspicions that have been raised."

Opposition lawmakers have seized on the issue, saying that a Singaporean company called Black Tidings, into whose account the Guardian newspaper said the payment was made, was a paper company.

The firm's business address is in a government housing complex in a suburban part of Singapore. A Reuters cameraman saw shoes and umbrellas in front of the address this week, but the company has no registered phone number.

Takeda said on Monday he believed it was not a paper company.

The Singapore account into which the money was allegedly deposited was controlled by Ian Tan Tong Han, a friend of the younger Diack, the Guardian reported.

The elder Diack, a former International Olympic Committee (IOC) member, is under a French police investigation for corruption at the IAAF, athletics' governing body. The IOC has said it has been in touch with French magistrates over the case.

Japan, which in 2013 beat Istanbul and Madrid to host the games, has been embarrassed by a number of woes since then, including scrapping the design for the centerpiece Olympic stadium, delaying construction.

Last month, it finally selected a new games logo after the previous one was withdrawn due to questions about plagiarism.