Authorities in Japan have raided six of the country’s largest ice-cream firms for allegedly colluding to raise the price of their products, provoking anger from frozen snack aficionados as they face a cruel summer ahead.

Officials from the Japan Fair Trade Commission (JFTC) on Tuesday carried out searches of the corporate headquarters of Akagi Nyugyo, Ezaki Glico, Lotte, Meiji, Morinaga Milk Industry and Morinaga & Co due to suspicions they had violated antimonopoly laws.

An official at the JFTC told the Guardian that it is not issuing a statement on the raids, but all six companies have confirmed they are under investigation by the commission and say they are fully cooperating.

The companies are suspected of colluding to use inflation in food prices to raise the prices of their products beyond the increase in raw material costs. Senior executives in the companies face allegations they held meetings and exchanged emails for years to coordinate the timing and scale of retail price rises for ice-creams and other frozen desserts, according to news agency Kyodo and public broadcaster NHK.

Public broadcaster NHK covered the raids in its main evening news bulletin, using a graph to show viewers how the price of two flagship frozen delights – Meiji’s ice-cream and Morinaga Milk’s six-pack choco-ice bites – jumped in lockstep four times between June 2022 and September 2025.

Morinaga Milk issued a statement on its website saying it was “subject to an on-site inspection by the Japan Fair Trade Commission on suspicion of violating the Antimonopoly Act. We take this very seriously and will cooperate fully with the commission’s investigation.”

According to sources familiar with the matter, this is the first JFTC investigation into a suspected ice-cream-related price cartel.

The Japanese market for ice-cream and frozen snacks hit a record 663bn yen ($4bn) in the fiscal year to March, driven by increasingly hot summers and price rises.

Japan’s already sweltering and sweaty summers are being intensified by climate breakdown, with record high temperatures being logged regularly in recent years.

In April, authorities announced a new term for days when the mercury tops 40C, kokusho, which translates as “cruelly hot”.

Adding to this summer’s woes are shortages in air-conditioner pipe coverings. The coverings of the pipes contain naphtha, the supply of which has been disrupted by the Middle East crisis, hitting installations of new air-conditioner units.