Lower house member Masatoshi Akimoto quit the ruling Liberal Democratic Party on Saturday in the wake of allegations that he accepted bribes from a wind power company, the LDP said.
His resignation from the party, tendered and accepted on Saturday, comes a day after Tokyo prosecutors searched his offices and home in connection with the allegations involving Japan Wind Development Co., prompting him to quit as parliamentary vice foreign minister.
The prosecutors on Saturday also searched the home of the Tokyo-based wind power company's president, Masayuki Tsukawaki, suspecting that he gave Akimoto, 47, a bribe in the form of investments in a racehorse owners' group effectively run by the lawmaker, according to sources close to the matter.
Tsukawaki's lawyer has denied the allegation, saying the company president jointly ran the racehorse group and that around 30 million yen he paid to it was not meant to be money personally given to the lawmaker.
Japan Wind Development was bidding for offshore wind power projects in Aomori Prefecture and other locations.
During a session of the House of Representatives in February 2019, Akimoto said he wanted to see wind power facilities developed in the sea off Aomori and hoped no excessive or unnecessary restrictions were placed on such projects.
LDP Secretary General Toshimitsu Motegi said in a statement issued after Akimoto's resignation that his departure from the party is "extremely regrettable" and the party hopes he will "account for his actions and clarify the allegations."
For around a year through October 2018, Akimoto served as parliamentary vice minister at the Ministry of Land, Infrastructure, Transport and Tourism.
During his stint, he pushed for legislation setting uniform rules for offshore renewable energy development in a bid to promote wind power. The legislation was enacted in November 2018.
Based on the legislation, the government designated three marine zones in Akita and Chiba prefectures for electricity generation for up to 30 years.