Upper House lawmaker Takao Koyama, arrested earlier this month on suspicion of taking bribes from the mutual aid foundation KSD, tendered his resignation from the Diet Monday, a senior in the chamber from the Liberal Democratic Party said.
House of Councilors President Yutaka Inoue accepted Koyama's letter of resignation.
Kakuji Yanagawa will replace Koyama based on the LDP's proportional representation roster.
Koyama's resignation before Wednesday was expected to minimize the impact of the KSD scandal on the party and on Diet deliberations, as the opposition camp was poised to submit a motion calling for his resignation on the first day of the regular session, LDP sources said.
Koyama, 57, was arrested Jan. 16 on suspicion of taking 20 million yen in bribes in 1996 from KSD, a foundation under the former Labor Ministry, in exchange for asking questions on its behalf at Diet panels. He left the LDP shortly after his arrest.
The KSD scandal widened to include the resignation last week of Fukushiro Nukaga as state minister for economic and fiscal policy and information technology.