How have you come to the conclusion that BDO is a reputable accounting firm? Can you provide their name, addresse, phone number and website so we can review it or are we just supposed to rely on your word?
BDO is one of the worlds largest accounting/auditing firms. It's not one of the Big 4, but it's right behind them. Many people recognize their name as one of the major account firms. If you want to check them out, just go to BDO.com. They are a huge recognized firm, so you probably don't have to worry as much about bribes and lack of manpower/resources to do an audit correctly. It is actually quite rare for a Chinese microcap to pay up for a big auditor.
Doesn't mean ONP is not a fraud, anything is possible (ex: Enron had a top auditor at the time). But if the business model is a fraud, why would it pay top dollar for good auditors, it would make more sense to pay little money for unskilled auditors that can easily be bribed.