Tokyo prosecutors and the country's fair trade watchdog on Friday searched the head office of ad giant Dentsu and the home of a senior official at the Tokyo Olympics organizing committee over alleged bid-rigging for the rights to organize test events for the 2020 games.

In the latest development in a series of scandals surrounding the massive sports event, held in 2021 amid the coronavirus pandemic, searches were conducted on suspicion of unfair restraint of trade. They also covered Tokyo-based event production company Cerespo.

Rigging is suspected in the 26 open bids held in 2018 for the rights to arrange test events, which were awarded to Dentsu and eight other companies as well as a consortium. The test events for checking potential problems with operations, security and guiding audiences were carried out between 2018 and 2021.