Lee Chang-beom, a South Korean national who also goes by the name Masanori Yamamoto and is president of the Derupara Group, was arrested on August 26 along with five other executives of the Tokyo-based company, including Kazuyuki Yuasa, head of the sales department, and Tomoyuki Konishi, who oversees the management division.
Police sources have told Japanese media that the six men are being questioned about promising cash payments of 3,000 yen (US$20) or 4,000 yen to about 250 staff if they voted for Yasuhisa Abe, who is the head of a pachinko industry association and was standing in his first election as a representative of the Liberal Democratic Party in the July race.
It is believed the company expected Abe to use his position to support initiatives to encourage a recovery in the pachinko sector.
The company staff were told to take a photo of their voting slip inside the booth to obtain the cash payment. Abe won more than 88,000 proportional representation votes but finished 20th among the 31 candidates, failing to secure a seat.
Offering to pay for a vote is a breach of the Public Offices Election Law.
