Police believe they have dealt a heavy blow to a vice racket which allegedly brought prostitutes from the mainland to Hong Kong, after arresting 35 people on Tuesday. The arrests included a couple who used their bank accounts to launder about HK$40 million believed to have been generated from illegal businesses over the past 12 months, police said. A Hong Kong man, 56, and his wife, 41, a mainland visitor, were believed to be the core figures of the syndicate, according to Chief Inspector Alan Chung of Kowloon West regional crime unit. Police are still looking for the other key figures of the syndicate. “Preliminary investigations showed that the syndicate brought mainland sex workers to Hong Kong and then arranged for them to stay in various hotels in Tsim Sha Tsui,” Chung said. Their pictures and details together with their contact numbers were put on a sex website, WeChat or other instant messaging apps. Callers were told to go to a hotel from for sex. “Clients were charged between HK$1,000 and HK$1,500 but the syndicate took 40 to 50 per cent of the earnings of sex workers,” police said. He said initial investigations showed the gang only served regular clients in an effort to avoid police detection. “We believe the syndicate had been in operation for about 12 months,” he said. “Its monthly turnover involved up to HK$1.5 million.” The Kowloon West regional crime unit began investigating the syndicate about three months ago. Officers posing as customers were sent to collect evidence. Around noon on Tuesday, dozens of officers raided four hotels in Tsim Sha Tsui and a number of other locations in the district. The key female suspect was picked up at one of the hotels when she collected money from several prostitutes. Officers seized about HK$80,000 she was carrying. At the same time, police arrested her husband in the nearby area. Police arrested the couple on suspicion of controlling persons involved in prostitution and living on the earnings of prostitution. Officers also rounded up 33 female suspected prostitutes from the mainland. The women were aged between 18 and 32 years old. The 35 suspects remained in custody and were being held for questioning on Tuesday evening. None of them has been charged. Police said investigations were still continuing.