Regarding the alleged bid-rigging of contracts for the Tokyo 2020 Olympics, Japan's competition watchdog has filed criminal complaints against the advertising behemoth Dentsu and five other companies.
Seven unnamed people were the subject of additional complaints from the regulator.
Following months of investigations into alleged corruption in the organization and sponsorship of Olympic and Paralympic events, the announcement was made.
Japan's largest advertising agency, Dentsu, is based in Tokyo.
The Japan Fair Trade Commission (FTC) announced on Tuesday that it had also brought complaints against the ad firms Hakuhodo DY Holdings, Tokyo Agency, Fuji Creative Corporation, Cerespo, and Same Two.
According to FTC investigator Goh Okumura, "We found that this is a malicious and serious case that will have a wide impact on people's lives.".
BBC requests for comments were not immediately answered by the businesses.
Bidding for contracts with Japan's industry, foreign, and education ministries has already been prohibited for Dentsu, Cerespo, and Fuji Creative for nine months.
Haruyuki Takahashi, an ex-member of the organizing committee for the Tokyo 2020 Olympics and a former executive at Dentsu, was detained last year on suspicion of accepting bribes from Olympic sponsors.
Mr. Takahashi was charged with receiving $380,000 (£315,600) in payments from Tokyo 2020 official partner and high-street business suit retailer Aoki Holdings. Allegations against Mr. Takahashi have been refuted.
Aoki Holdings' former chairman and two other executives were also reported to have been detained, according to officials, in connection with the investigation.
In 2013, Tokyo won the right to host the Olympics over Madrid and Istanbul.