Standard Chartered PLC is suing Chen Jihong, the Chinese businessman at the centre of a suspected fraud at China's Qingdao port, joining a list of firms that have taken legal action to reclaim their losses.

Standard Chartered is the fourth company to say it has started legal action to recoup losses since Chinese authorities launched an investigation into whether a private metals trading firm, Decheng Mining and its related companies, used fake warehouse receipts at Qingdao Port to obtain multiple loans secured against a single cargo of metal.

Valerie Tay, a spokeswoman for the bank, confirmed that the bank has started legal proceedings against Chen.

The bank is suing for $35.6 million plus costs and interest, according to the court documents reviewed by Reuters on Monday. The amount is significantly smaller than its previous announcement last month that its total commodity-related exposure around China's Qingdao port was about $250 million.

Other firms that have launched legal proceedings include Standard Bank Plc, Citic Resources Holdings Ltd and China's Shanxi Coal International Energy Group.

Standard Bank said its total exposure to metals at Qingdao port was about $170 million, and it also has an exposure of $40 million worth of aluminum at other bonded warehouse facilities in Shandong province.

A native of southern China's Guangdong province who has since taken Singaporean citizenship, Chen is chairman of Qingdao-based Dezheng Resources Holding Co Ltd, which is the parent company of Decheng.

Western banks such as Standard Chartered, HSBC and BNP Paribas, which face restrictions in the domestic loan market in China, are active in the metals financing business where they give companies ready access to short-term credit in exchange for goods.