China's Qingdao port said on Wednesday it is investigating whether iron ore warehouse receipts were fraudulently used multiple times to raise finance from different banks, Xinhua news agency reported.
The probe is focussed on one trader with iron ore receipts, the Chinese news agency said. It follows a broad investigation earlier this year by Chinese authorities into the use of iron ore as collateral in financing deals.
While Xinhua reported that the probe was limited to iron ore financing, trading and warehousing sources have told Reuters it was also looking at the suspected multiple use of copper and aluminium warehouse receipts to raise financing.
Copper premiums in Shanghai fell on Wednesday after traders cited concerns over disruptions to some shipments from Qingdao, related to the probe. Port authorities in Qingdao said exports and operations were running normally.
(Reporting by Maytaal Angel; Editing by Dale Hudson)