Prosecutors arrested a former operations executive at the Tokyo Olympics organizing committee and three others on Wednesday over bid-rigging allegations, as yet another corruption scandal surfaces in the wake of the global sports event.

Tokyo prosecutors arrested the former executive, Yasuo Mori, on suspicion he played a leading role in rigging bids for contracts in planning games test events and running both the pre-games events and competitions during the Summer Games in violation of the anti-monopoly law.

Photo taken in Tokyo on Feb. 8, 2023, shows the building housing the headquarters of Dentsu Inc. (Kyodo)

The contracted amount to run the pre-games and competitions at the Tokyo Olympics and Paralympics in 2021 totaled around 40 billion yen ($303 million), a source close to the matter said.

The other three arrested are Koji Hemmi, a former executive at Japanese ad giant Dentsu Inc., and officials Yoshiji Kamata and Masahiko Fujino from event production companies Cerespo Co. and Fuji Creative Corp., respectively, both firms that won contracts to plan test events.

Prosecutors searched Wednesday the homes of Mori and Hemmi while Cerespo and Fuji Creative were also searched by the authorities in cooperation with the Japan Fair Trade Commission.

Mori, along with Hemmi, who served as his contact at Dentsu, and others used a list of companies assigned to each test event for the Tokyo Olympic and Paralympic Games to arrange successful bidders, the source said.

They exchanged emails with companies that prosecutors allege influenced the bidding process, the source said.

The former executive initially denied knowledge of the bid-rigging during questioning by prosecutors, but later admitted to the allegation after Dentsu officials said they colluded, the source said.

It is suspected the rigging took place in connection with 26 open bids held in 2018 for the rights to plan test events. These were awarded to nine companies, including Dentsu and fellow ad giant Hakuhodo Inc., as well as a consortium, for a total of 538 million yen.

The test events -- held to give organizers and sporting federations a chance to trial operations, security and crowd control -- were held between 2018 and 2021 before the Summer Games went ahead held after a one-year postponement due to the coronavirus pandemic

Tokyo Gov. Yuriko Koike said the arrest of Mori was "extremely regrettable." She said she has told the liquidation corporation for the now-dissolved committee to continue cooperating with the prosecutors' investigation.

The Japanese Olympic Committee said in a statement it takes the arrest "seriously." "We are not aware of the details and will monitor the developments closely," it said.

In the bribery scandal, Haruyuki Takahashi, former executive at the organizing committee, has been indicted four times on charges of receiving bribes totaling some 198 million yen in return for helping companies be selected as a sponsor or a marketing agent of the global event.

Takahashi, former senior managing director at Dentsu, had influence over the committee's marketing division which was charged with sponsorship selection, according to prosecutors.

Related coverage:

30-month sentence sought for ex-chairman in Olympic bribery trial

Contracts in Tokyo Olympics bid rigging case totaled 40 bil. yen

Dentsu officials admit to Tokyo Olympic test event bid rigging