International auction houses have become victims of China's thriving art market, with the emergence of a stream of companies seemingly related to the world's big three - Sotheby's, Christie's and Bonhams. Despite persistent legal action taken in Hong Kong and on the mainland, the pretenders keep appearing. The latest cases uncovered include companies that take after London-based auctioneer Sotheby's, founded in 1744. An advertisement for a Hangzhou , Zhejiang company literally known as Sufuby Art and Culture Planning/Curatorial was spotted in last month's issue of Collection World magazine on the mainland. The ad introduced Sufuby as an art consultancy specialising in Chinese antiques and works of art, featuring traditional Chinese characters instead of the simplified characters used on the mainland. The company's logo is of the same blue tone as Sotheby's. Sufuby is pronounced the same way and uses the same Chinese characters as Sotheby's Chinese name, Su Fu Bi. Another case is Beijing auction house Soft Bid, which calls itself Dong Fang Suo Fu Bi in Chinese, dong fang meaning 'eastern'. At times, the fakes even go beyond the art scene. There is a resort called Beihai Sufubi Gallery Hotel on Silver Beach, Guangxi. A mainland hotel-booking website introduces the resort as a boutique art hotel with four art galleries. The hotel's name uses the fu character meaning 'good fortune'; Sotheby's uses a 'fu' meaning 'wealth'. Sotheby's was not available for comment. It is understood that the firm is investigating these newly found cases. Meanwhile Bonhams, founded in London in 1793, has seen its previous Chinese name Bao Long - meaning 'treasure dragon' - resurface in the name of a new auction firm called Shanghai Baolong. In August, the State Administration of Cultural Heritage approved Shanghai Baolong to auction a range of objects that included paintings, banknotes, furniture and textiles. In Hong Kong, Christie's, founded in 1766, is also not spared the fakes. It sued a company called Chritrs in August for infringing its registered trademark. Chritrs' Chinese name is pronounced as Jie Si De - the same as Christie's - except that its written character for de means 'morality', whereas the auction house uses the character that means 'get' or 'catch'. Christie's declined to comment on the case, as it is going through legal proceedings.