A GANG of mainland pirates alleged to have beaten 23 crewmen to death after hijacking a vessel managed by a Hong Kong company launched their attacks from a boat previously used in legitimate public security operations, a Chinese court heard yesterday. Their trial, one of the largest piracy cases in modern China, entered its second day at Shanwei Intermediate People's Court in Guangdong. Thirty-eight defendants, aged 21 to 60, face charges of murder, robbery, possession of firearms and handling stolen property. It is alleged they were involved in three acts of piracy in the South China Sea. In the last attack, 23 crew members on board the Hong Kong-owned Cheung Son were robbed and killed one by one after being held on board for 10 days. Yesterday, one defendant, mechanic Zhang Fensheng, 42, who denies a charge of robbery, told the court that their ship had sailed from an official border defence pier. 'I did not dare to ask what they [the other defendants] were doing on the boat as they alighted from the pier used by the border defence officers and they were all wearing uniforms,' he said. Zhang told the court he did not know they had robbed ships as he was working in the ship's engine room. Cai Mutong, a fisherman in Lufeng, who also denies robbery, said the ship with uniformed personnel aboard usually left the pier in Chaozhou at night to search for their targets. The court also was told the alleged pirate ship had served as a border defence vessel for a private company licensed by mainland authorities to carry out Customs inspections. The policy of using private contractors to carry out Customs duties has since been scrapped. Shanwei businessman Huang Daming, 33, also charged with robbery, said the company's licence was terminated in August last year and he had been approached to manage the ship. He was later approached by one of the main suspects, Weng Siliang, who asked him for use of the ship on loan, the court heard. 'He told me the ship would be used in Customs duties in Ningbo,' Huang said. After the alleged Cheung Son hijacking and killings, the piracy ship was sold through Weng for 300,000 yuan (HK$283,000), of which Huang received 100,000 yuan. New crew were hired and the ship was later was sold to an unknown foreign party. The hearing is to continue until Thursday.