Prosecutors have questioned a ruling party lawmaker over his alleged ties with a Chinese company that showed interest in joining a casino project and is suspected of violating the foreign exchange law, sources close to the matter said Wednesday.

Tsukasa Akimoto, 48, a House of Representatives member of the Liberal Democratic Party, was interviewed on a voluntary basis by the Tokyo District Public Prosecutor's Office in connection with the Chinese company, which allegedly brought into Japan a large amount of cash without notifying customs authorities, the sources said.

Akimoto is a leading promoter of casino resorts, which have been recently legalized in Japan. He was in charge of a so-called integrated resort project involving a large hotel and conference facilities in addition to a casino from August 2017 to October 2018 as a senior vice minister at the Cabinet Office.