Police have discovered an abandoned poultry and pig farm in the New Territories converted into a 24-hour brothel, servicing up to 50 customers a day. The brothel, which also served as a home for its mainland prostitutes, was discovered in a remote village during an anti-vice operation on Wednesday night. It is believed to have been operating for about a year and controlled by a triad gang that went across the border to recruit women to work as prostitutes, according to Superintendent Chiu Ming-wah, of the Organised Crime and Triad Bureau. The farm, in a remote part of Pak Sha Tsuen, Yuen Long, has been abandoned for more than two years and is surrounded by a fence. Tin huts are divided into five bedrooms and bathrooms and there is a sitting room where prostitutes lined up when customers arrived. 'It only took in regular customers who had to tell the secret code to gain access to the brothel,' Mr Chiu said. 'It was equipped with closed-circuit TV, with a pin-hole camera concealed in its main gate to monitor the area outside the farm. 'While under our surveillance, the brothel had clients coming in around the clock and its peak time was between 5pm and 8pm. We believe up to 50 customers visited the brothel a day and they included workers from nearby garages and farms. 'It is the first time in my knowledge we have discovered a brothel operating in a setting like this.' Officers are investigating whether the owner of the farm, who has not been arrested in the operation, is linked to the vice syndicate. A police source said the brothel was controlled by a Wo Shing Wo triad gang. Its leader, his two followers and nine mainland prostitutes were arrested during the raid on Wednesday night. It was just one of the raids in an anti-vice crackdown against four Wo Shing Wo gangs that allegedly control a large portion of Yuen Long's vice trade. Police said the operation, involving about 350 officers, came after a six-month undercover investigation. A further 26 alleged triad members, including at least two office-bearers and 90 women - mostly mainland prostitutes - were arrested in the seven-hour operation that ended at 3am yesterday. During the operation, officers raided the farm, another 22 brothels and nine residential units in Yuen Long. Mr Chiu believes they have smashed the four vice syndicates, which are believed to have generated an income of up to $45 million a year. All the suspects, who are aged between 22 and 60, were being held for questioning last night. In a separate anti-vice operation that ended at 2.30am yesterday, 123 alleged sex workers - 122 mainlanders and one Vietnamese - were rounded up in Mongkok.