Japan's competition regulators have filed criminal complaints against the advertising giant Dentsu and five other firms over the alleged bid-rigging of contracts for the 2020 Olympics.
The announcement follows months of investigations into alleged corruption in the planning and sponsorship of Olympics and paralympics events.
On Tuesday, the Japan Fair Trade Commission FTC said it had also filed complaints against advertising agencies Hakuhodo DY Holdings, Tokyo Agency, Fuji Creative Corporation, Cerespo and Same Two.
Goh Okumura, an investigator at the FTC, said that this was a malicious and serious case that will have a huge impact on people's lives.
Dentsu, Cerespo and Fuji Creative have been banned from bidding for contracts with Japan's industry, foreign and education ministries for nine months.
In the last year, Haruyuki Takahashi, an ex-member of the Tokyo 2020 Olympics organising committee and previously an executive at Dentsu, was arrested on suspicion of receiving bribes from Olympic sponsors.
Takahashi was accused of taking $380,000 315,600 in payments from high street business suit retailer Aoki Holdings, an official partner of the Tokyo 2020 games. Takahashi denied the allegations.
A former chairman and two other executives of Aoki Holdings had been arrested in connection with the case, officials said.