FEARS that Wan Chai's bar strip might become another Patpong Road have sparked a major police crackdown. A special patrol was put on over the weekend as one of a series of steps which will be taken by Wan Chai police in their efforts to keep a tight control on the bars and the overseas workers flooding into Hongkong to work as dancers. Led by deputy district commander, Senior Superintendent Martin Sampson, and district operations officer, Chief Inspector David Lorimer, a team of 14 uniformed and plain-clothes policemen made a five-hour inspection of the area. They took with them two members of the Television and Entertainment Licensing Authority, which issues the permits for the dancers and sets dress and conduct codes for the bars. The Immigration Department has also been encouraged to get involved. While a department spokesman said the performers must have proof of professional qualifications, the visa procedure was described as a ''rubber stamp'' exercise by the mamasan of one Wan Chai bar. ''The numbers [of girls] are building up. If we're not careful it will get out of hand,'' Mr Sampson warned. ''We don't want this turning into a Patpong Road or Bugis Street,'' he added, referring to the notorious red light districts of Bangkok and Singapore. ''To some extent, it [the crackdown] is trying to make some people realise there is a problem.'' Entertainers from the Philippines, Thailand and most recently Malaysia are inundating the increasing number of dance girl clubs along Lockhart Road. ''There is a suggestion some of them are working as prostitutes and obviously we take that kind of allegation very seriously, particularly if the girls themselves are being controlled or manipulated in any way by the operator of the bar or anybody else,'' Mr Lorimer said. According to social workers on the frontline, that is exactly what is happening to a small band of girls. A volunteer social worker, who insisted on remaining anonymous for her own safety and those of the girls she assists, single-handedly helped 20 bar girls escape from intolerable conditions. The police and social workers believe there are four main syndicates in Manila, Bangkok and Penang with long-established supply links to Hongkong. Some women who land at Kai Tak Airport are expecting to be cashiers or receptionists, but can be subjected to a terrifying ordeal. ''They are locked up, beaten up and raped repeatedly if they don't comply. It really is horrifying, but it goes on,'' she said. Watched closely day and night by two guards, the girls are forced to sleep with 10 to 20 customers every day, claim the social workers. Mrs Cynthia Tellez from the Mission for Filipino Migrant Workers said a worrying trend was emerging. ''Those being trafficked are getting younger and younger: the thinking is that such girls are less likely to be AIDS carriers,'' she said.