Japan’s Fair Trade Commission searched the premises of the country’s largest beer makers on Wednesday over suspected price-fixing.

Asahi Breweries and Kirin Holdings confirmed the searches and said they would cooperate fully. Kirin said its subsidiary, Kirin Brewery Company, was searched on suspicion of violating the Antimonopoly Act. It said the effect on its financial results has not been determined.

There are reports that Sapporo Breweries and Suntory Spirits were also searched. Shares in Asahi, Kirin and Sapporo fell after the news. Suntory is not publicly listed.

The Japan Times reported that the inquiry centres on price rises announced in April last year and October 2022. The companies cited higher raw material, energy and transport costs.

The commission has not yet commented on the searches. The companies are accused only of suspected violations and no finding has been made.