A lawmaker already indicted for bribery in a casino graft scandal was served a fresh arrest warrant by prosecutors Wednesday on suspicion of further witness tampering.

In the latest arrest, Tsukasa Akimoto, a 48-year-old House of Representative member formerly of the Liberal Democratic Party, is suspected of asking two acquaintances to offer money to Katsunori Nakazato, 48, a former advisor to Chinese gambling operator 500.com Ltd., in exchange for false court testimony. The company was lobbying for a casino license in Japan,

Daisuke Matsuura, 51, who allegedly offered Nakazato the witness-tampering deal on behalf of Akimoto, told investigators he made the offer at the behest of the lawmaker. Matsuura has been arrested over the witness-tampering allegation, while a 49-year-old company executive has been indicted on the same charge.

Following his initial arrest in December, Akimoto was rearrested on Aug. 20 for allegedly conspiring with supporter Akihito Awaji, 54, and another man to offer Masahiko Konno, 49, a former adviser to 500.com, a total of ¥30 million ($283,000) at a hotel in Naha, Okinawa Prefecture, sometime between June and July in exchange for giving false testimony.

Awaji, a company executive who lives in Tokyo, has told prosecutors they were acting on behalf of the lawmaker, a person familiar with the matter has said. Akimoto, however, has denied involvement.

Akimoto oversaw an initiative for legalized casinos to be operated in Japan at so-called integrated resorts with hotels and conference facilities. He was a senior vice minister in the Cabinet Office for about a year from September 2017.

Konno and Nakazato gave a total of ¥7.6 million worth of bribes to Akimoto, according to the indictment.