Note that apparently in the mean time it has become even more difficult to open a business bank account in HK (to the extent that some startups complain that they can't get a bank account).
So, research that carefully before going down that route.
Good question. Don't know whether it's a reaction to US FATCA and other governments and supranational bodies cracking down on tax havens (which HK does not want to be seen as), but the fact remains that while 10 years ago you could stroll into any bank and open an account, in the last couple of years you need to provide very compelling reasons and documentation. (Note that the banks tend to not comment on their policies and decision criteria - so they might well tell you that they'll open an account, but when you walk in they will (in good old Chinese fashion) decline for some mysterious reason and recommend that you try "maybe tomorrow".)
So, research that carefully before going down that route.