Tokyo prosecutors have arrested the chairman of Nihon University, one of Japan's largest universities, on suspicion of tax evasion.

Tanaka Hidetoshi is accused of evading 53 million yen, or roughly 470,000 dollars, in income tax by excluding kickbacks from contractors from his income statements in 2018 and 2020.

The arrest came after prosecutors found cash worth about 880,000 dollars at Tanaka's home during raids in connection with a bribery case involving a former board member of the university.

The former board member, Inoguchi Tadao, has been indicted for a breach of trust along with the former head of a medical corporation, Yabumoto Masami, for causing a loss to the university over a contract for its hospital.

The two allegedly set up unnecessary go-betweens, including a company effectively run by Yabumoto, when the university procured medical devices.

They reportedly told investigators that they provided a large amount of cash to Tanaka.

Sources say Tanaka denied receiving the cash during voluntary questioning by prosecutors.