As the investigation continues into the suspected bid-rigging case involving the top aide to Lower House member Muneo Suzuki, prosecutors now believe that the initiative for the scheme was taken by a Tokyo-based engineering firm.
The company, JGC Corp., was trying to win a contract for a government-funded construction project on a contested island northeast of Hokkaido.
Akira Miyano, 53, Suzuki's secretary, was arrested Tuesday on suspicion of interfering in the bidding process for the building, locally known as "Muneo House" on Kunashiri, one of the Russian-held islands off Hokkaido that are claimed by Japan.