Japanese officials have raided the country’s biggest beer makers over allegations they worked together to raise the price of their beverages.

Asahi and Kirin confirmed to the BBC their premises had been searched by the Japan Fair Trade Commission, adding that they would fully cooperate with the government authority.

There are reports Sapporo Breweries and Suntory Spirits were also raided. Both firms have been contacted for comment.

Asahi, Kirin and Sapporo all saw their share price fall after news of the investigation broke on Wednesday. Suntory is not publicly-listed.

According to the Japan Times, the investigation centres on the companies raising their prices in April last year and in October 2022.

All four companies announced increases, citing the rising cost of raw materials as well as other factors such as energy and transportation.

Kirin Holdings said its subsidiary, Kirin Brewery Company, was searched “on suspicion of a violation of the Antimonopoly Act”.

It said it takes the matter “very seriously”, adding it would “fully cooperate with the Japan Fair Trade Commission’s investigation and any requests for cooperation”.

Kirin Holdings said: “At present, the impact of this matter on the company’s financial results has not been determined. The company will promptly disclose any material developments as they arise.”

Asahi Breweries said it was “subject to investigation by the Japan Fair Trade Commission regarding a suspected violation of the Act on Prohibition of Private Monopolization and Maintenance of Fair Trade”.

It added: “We will fully cooperate with the commission.”

The Japan Fair Trade Commission has been contacted for comment.