I searched on internet, and find many suppliers, some of them is in HONGKONG, and some in China. As far as I know hongkong is belong to China if i am not wrong.
Some claimed that they are in hongkong, but their website name includes China, like Chinabuye, Chinavasion, ePathChina etc. I like these sites. But I really have some concern to choose China supplier or Hongkong supplier, please advise if you know it. thank you!

although HK is now "part" of mainland China, there are still different rules to the 2 (HK will keep the old British rules until 2047). for example visa wise a European traveler would need a visa to go to China but not HK. also, you have to go through passport control to go from HK to China.

also in China they use the YUAN money (RMB) while in HK they use HK Dollar(HKD). so check which one will give you the best rate for your purchase.

official language in HK is Chinese and English so people will understand you better than in China where the official language is Chinese.

staying in HK is more expensive than anywhere in mainland China so think about that when going on business trips.
also many suppliers have offices in HK but their factories are in China(cheaper labor) so that may be the reason for your misunderstanding.

your hunch is correct--please go to the nearest Chinese embassy commercial section to verify the name of the company----now that you mentioned Hong Kong let me tell you that some so called "ChinaBuye" businessmen are dealing in computer parts that are rejected by quality control of the actual genuine manufacturers---they buy these parts in lots for cheap---recondition them so that they will work 3/6 months at the most and offer them to businessmen from the Indian sub continent------take the power supply for computer as an example--i opened it and found joints and wiring jumpers on the solder side which a new original factory made part is not supposed to have---!!!