Japanese police officials are looking into the 2013 murder of a restaurant magnate. This comes after an imprisoned gangster suspected of shooting and killing him was arrested.

Ohigashi Takayuki was gunned down in front of the headquarters of Ohsho Food Service in Kyoto. The company operates hundreds of Chinese restaurants across Japan and overseas.

Investigators arrested Tanaka Yukio on Friday. He has been serving a prison sentence for an unrelated shooting incident. Tanaka is a senior member of a Yakuza group based in Fukuoka Prefecture.

But police have not been able to establish a direct connection between the gangster and Ohigashi or his company.

The company set up a third-party committee after Ohigashi was killed. The committee was tasked with evaluating corporate governance at the firm.

It reported in 2016 that the company had repeatedly engaged in inappropriate deals involving a business group. Shady real estate transactions were among the actions cited. The company reportedly lost more than 100 million dollars.

The committee said Ohigashi was trying to improve the situation.

Investigative sources say police officials have questioned an individual who was the business group's manager. The authorities want to find out if the inappropriate deals had anything to do with Ohigashi's murder.

The police apparently asked about the flow of funds from the company to the business group that the third-party committee mentioned in its report.