The president of Japanese advertising giant Dentsu Group acknowledged corporate responsibility for suspected bid-rigging on contracts for the Tokyo Olympics and Paralympics, NHK and other local media reported.

Dentsu President Hiroshi Igarashi made the comments during questioning by the Tokyo District Public Prosecutor's Office, NHK said Saturday, citing a source it did not name. Officials for Dentsu and Tokyo prosecutors could not immediately be reached for comment outside of office hours.

The Fair Trade Commission is making final arrangements to file a criminal charge against six companies, including Dentsu, for suspected violation of antitrust laws, NHK said. The indictments could come as soon as Tuesday, broadcaster NTV reported separately.

Tokyo prosecutors raided the offices of Dentsu last year as part of a probe into possible collusion with other companies involving Olympics contracts set in 2018, according to broadcaster NTV.

The Tokyo Games were postponed in 2020 by a year due to the COVID-19 pandemic and yielded a hefty $3.3 billion from sponsors by the time it kicked off in 2021. It was held without spectators due to the virus.

Dentsu Inc. said in a statement in November it was fully cooperating with authorities. The ad firm oversaw Olympic-related efforts before becoming a wholly-owned unit of Dentsu Group after a change in the company’s holding structure.

Last year, local prosecutors made multiple arrests while serving charges against a former Tokyo Olympics organizing panel member, widening their investigations into alleged bribery in the games sponsorship process.