TOKYO, Oct 7 — Japanese authorities raided four major beer manufacturers today over suspicions they colluded to hike beverage prices in a violation of anti-monopoly laws, a source familiar with the matter and the firms said.

Under investigation are Asahi Breweries, Kirin Brewery, Sapporo Breweries, and Suntory — four giants that reportedly make up around 90 percent of Japan’s beer market share.

In a first, the Japan Fair Trade Commission (JFTC) conducted on-site inspections to probe “the allegations regarding a wholesale beer pricing cartel”, the source, requesting anonymity, told AFP.

The price-fixing has likely been unfolding over the past few years, during which representatives from the four companies are believed to have met up periodically to discuss pricing and the timing of the hike, the source said.