Hong Kong, to the best of my knowledge, is not a sanctioned jurisdiction. However, there may be individuals/entities that are sanctioned parties operating in Hong Kong. Unless you can successfully complete name screening on all parties I wouldn't process the transaction(s). Especially if it's for a non-critical customer.
"100 victories in 100 battles isnt the most skillful. Subduing the other's military w/o battle is the most skillful." Sun-Tzu