Japan’s beer industry has been shaken by a major antitrust probe, with authorities raiding the country’s four biggest brewers over claims they may have worked together to lift prices. The investigation reaches into a market worth more than 1 trillion yen ($A9.1b) a year and centres on companies whose brands are also familiar to Australian drinkers. Japanese competition regulators carried out on-site inspections of Asahi Breweries, Kirin Brewery, Sapporo Breweries and Suntory Spirits on Wednesday as part of a compulsory investigation into suspected price fixing.

The four brewers dominate Japan’s beer business, controlling more than 90 per cent of the market, and investigators are examining whether they co-ordinated the timing and size of wholesale price rises over several years. That includes beer, low-malt beer and other beer-like drinks sold across Japan. According to local reports, the Japan Fair Trade Commission suspects sales executives from the companies met separately after regular gatherings of the Brewers Association of Japan and discussed how much to lift prices charged to wholesalers.

Authorities are now looking into whether those moves pushed up costs for retailers and restaurants, with the burden ultimately flowing through to consumers. The investigation is especially significant because compulsory investigations are reserved for the most serious cases. They allow officials to enter offices and seize evidence under court warrants, and reports in Japan indicate the watchdog is also considering whether criminal complaints should be filed with prosecutors. All four companies have confirmed they are under investigation and have indicated they will co-operate.

Suntory said it was “undergoing an on-site inspection by the Fair Trade Commission on suspicion of breaching the anti-monopoly act in relation to its alcohol trading activities”.

“The investigation cited in media reports concerns Asahi Breweries in Japan and is entirely unrelated to Australian operations,” an Asahi spokesperson in Australia told the ABC. Japan’s brewers have faced a long-term decline in domestic demand amid population loss and changing drinking habits. Official figures reported in Japan show domestic sales of beer and low-malt beer totalled about 1.61 trillion yen, or about $A14.62 billion, in 2024.

The investigation follows a series of near-simultaneous price increases across the industry. The four brewers all raised prices in October 2022 and again in April 2025, publicly linking those decisions to higher costs for ingredients, packaging and transport. More recent pricing revisions also followed changes tied to Japan’s liquor tax overhaul. Asahi is Japan’s biggest brewer and the company behind Super Dry, the crisp lager that helped transform the domestic beer market decades ago before becoming a major international brand.

In Australia, Asahi has a large footprint through Asahi Beverages, which also owns a wide stable of local brands. Kirin is one of Japan’s oldest brewing names and has a broad drinks business that stretches well beyond beer. Its reach in Australia comes through Lion, the major beverages group behind brands such as Tooheys, XXXX and Hahn, giving it a long-established presence in local pubs and bottle shops as well as through Kirin Ichiban.

Sapporo, founded in the 19th century, is widely regarded as Japan’s oldest beer brand and has built an international following around its premium lager. In Australia, Sapporo beer has also been brewed locally under partnership arrangements. Suntory, best known globally for its whisky and premium drinks portfolio, is another giant of Japanese beverages. It has been expanding strongly in Australia through Suntory Oceania.

If regulators conclude the companies breached Japan’s antimonopoly laws, penalties could potentially including financial surcharges and orders to change business practices.