The Tokyo District Public Prosecutor's Office's special investigation squad arrested Kazutaka Yonekura, 48, the founder and former president of Japanese artificial intelligence developer Alt, and three others on Thursday on suspicion of padding the firm's sales in violation of the financial instruments and exchange law.

The other three include Yusuke Hioki, 34, also a former president of the Tokyo-based company. The special squad did not reveal whether the suspects have admitted to the allegations against them.

They allegedly submitted to the Kanto Local Finance Bureau in September 2024 financial statements, in which the company's sales in the period from January 2022 to June 2024 were inflated by about ¥8.4 billion.