The JFTC is also investigating whether the companies took advantage of inflation to raise prices beyond what was justified by a spike in raw ingredient costs, according to Kyodo News.
Five of the companies issued statements on Tuesday or on Wednesday saying their offices had been raided by the JFTC and that they “would cooperate with the investigation”.
Natsuyo Suzuki of Akagi Nyugo also confirmed to AFP that the firm would work with investigators following an “on-site inspection”.
If the JFTC concludes that there was a cartel, the antitrust watchdog will order the firms to improve their business practices and pay a fine.
In the fiscal year ending in March, ice cream sales in Japan hit a record high of more than 660 billion yen, according to the Japan Ice Cream Association, as the country sweltered through its hottest summer since records began in 1989.
