Recent announcements from governmental authorities in China indicates that negative Internet postings will be required to be removed promptly by Internet Service Providers, and that true names of Internet users will be mandatory. Even if you are using compliance staff who are competent in Mandarin, this present a problem.
Postings on corruption, and other crimes committed by Chinese Politically Exposed Persons (PEPs), they will either not appear, due to fear of punishment by the State, or will be summarily taken down by the ISP. Therefore, you cannot expect to find any negative information on Chinese PEPs, during your due diligence investigation. You may even fail to identify that new client as a PEP.
It is suggested that you will need to engage experienced investigators, in the field, probably in Hong Kong, to vet new affluent Chinese clients.