The 78-year-old is alleged to have received around ¥45 million (£274,000/$330,000/€326,000) from major business suit retailer Aoki Holdings Inc. after a company he headed reached a consulting deal with the firm.

Aoki's Olympic sponsorship was announced about a year later.

Investigators in Japan are reportedly looking into the flow of funds and what influence it had on the holding of the Olympic and Paralympic Games, as Takahashi was deemed a quasi-civil servant in his capacity on the Tokyo 2020 Organising Committee, which was officially disbanded last month.

Accepting money or gifts related to his duties could constitute bribery and Takahashi could face corruption charges.

Several investigators were seen entering Takahashi's home in Tokyo's Setagaya Ward amid heavy rain, Japanese press agency Kyodo News reported, as well as the main offices of Japan's largest advertising agency Dentsu Inc. in Minato Ward, where Takahashi was also a former senior managing director.

Many Dentsu employees were seconded to the Tokyo 2020 marketing division, which was responsible for selecting sponsors for the Games.

Prosecutors are also looking into whether Takahashi exerted any influence in the selection of sponsors.

According to a source familiar with the case, the consulting firm headed by Takahashi signed the deal with Aoki worth ¥1 million (£6,000/$7,300/€7,250) per month in September 2017.

Aoki announced in October 2018 that it had sealed an "official supporter" contract with Tokyo 2020.

The contract allowed Aoki to use the events' emblems for business purposes and sell officially licensed products, including suits bearing the emblems.

The company has sold more than 30,000 suits and jackets bearing the emblems to the public since summer 2019.

It also provided Japanese athletes with uniforms for the Opening Ceremony of the Olympic and Paralympic Games. 

Takahashi has denied any wrongdoing.

Seiko Hashimoto, the President of Tokyo 2020 and who is a member of the House of Councillors for the ruling Liberal Democratic Party, told the Japanese media that the investigation taking place was "extremely regrettable".

Aoki Holdings' former chairman and founder Hironori Aoki, who retired last month, told prosecutors, after agreeing to answer their questions, that he had "high hopes in Takahashi's power" given his background.

It is not the first allegation of bribery involving a senior Tokyo 2020 official.

Tsunekazu Takeda, the former President of the Japanese Olympic Committee, resigned in 2019 after being tied to an investigation into bribes reportedly paid to International Olympic Committee members in the 2013 vote.