A Chinese company executive who allegedly bribed lawmaker Tsukasa Akimoto over a plan to open a casino resort in Japan had told his head office in Shenzhen, China, that he would “need funds for bribery,” sources close to the matter said Monday.

Sources also said that Chinese online sports lottery provider 500.com had documentation of the money that allegedly ended up in Akimoto’s hands.

Investigators suspect that 500.com approached Akimoto, who was the state minister in charge of the government plan to introduce casino resorts in Japan, and gave him money on multiple occasions in hopes of receiving preferential treatment for its bid to open a gambling facility.

Akimoto, a 48-year-old member of the Lower House, was arrested last week by the Tokyo District Public Prosecutor’s Office on suspicion of accepting ¥3.7 million in bribes, including ¥3 million in cash, from 500.com, which had set its sights on building a casino in Hokkaido.

The remaining ¥700,000 allegedly came from 500.com in the form of travel expenses for his family to visit Hokkaido in February 2018. They reportedly made the trip at the invitation of the company.

Prosecutors suspect that Akimoto received the cash from three people connected to 500.com during a meeting at his office on the fifth floor of a building for lawmakers in Tokyo on Sept. 28, 2017, when the Lower House was dissolved for a general election, as a contribution for his re-election campaign.

Akimoto has admitted that he knows the three people, who have been arrested for allegedly offering the bribes to the lawmaker, according to a lawyer who met with him after his own arrest. But he categorically denied receiving the ¥3 million. He also claimed that he does not remember the September 2017 meeting, according to the lawyer.

Regarding his family’s visit to Hokkaido, Akimoto suggested he paid for the trip himself and that he had asked his secretary to take care of the payment, the lawyer said.

According to investigative sources, the three other people under arrest, including Masahiko Konno, 48, and Katsunori Nakazato, 47, both advisers for 500.com, have provided prosecutors with details about the September 2017 meeting with Akimoto and why the company invited him and his family to the trip to Hokkaido, .