Police in Shangdong province are looking into the death from unnatural causes of the deputy commissioner of customs at Qingdao port, which is under investigation over an alleged commodity financing fraud, Xinhua News Agency reported on Thursday.

Xinhua said Bian Peiquan died on Aug 5, but it gave no further details.

Officials at Qingdao customs did not respond to telephone and fax requests for more information. Qingdao police declined to comment, saying only that the investigation was continuing.

The fraud inquiry has prompted global trading houses and banks, including HSBC and Standard Chartered, to launch lawsuits because of their estimated $900 million exposure.

It was not clear whether Bian's death was linked to the scandal, but his death comes after a number of high-profile suspected suicides of executives from large State-owned firms since President Xi Jinping launched a campaign against graft last year.

Bian, 59, was in charge of operations at the service center and staff training, according to the customs website.

A source who knew him personally said his administrative role would have given him limited exposure to the port's business activities.

Fraud investigators are examining claims that a company called Decheng Mining used fake warehouse receipts to obtain multiple loans at Qingdao port.

Decheng Mining has not commented on the case.

Reuters