A HONG Kong businessman with American citizenship is being detained in China after Public Security Bureau (PSB) agents burst into a hotel room and arrested him as he was signing a contract with a Hunan company, say his family. Dr Philip Cheng, chairman of Zhuhai Golex Limited and former head of the Department of Journalism at the Chinese University, has allegedly been detained in Changsha, Hunan, since Thursday. His family have contacted United States congressmen Thomas Foley and Slade Gordon asking for their intervention. Zhuhai Golex Limited general manager Li Guan-hua, who said he witnessed the raid, claimed his boss was allowed to fax a hand-written note from his detention centre to his family, but nothing more has been heard from him or the PSB. His wife, Marie, and sons Norman, his business partner in China, and Alan are doing everything they can to get their father released. Alan, an associate editor of Asia Inc magazine, is trying to mobilise support in Washington, while Norman is travelling to Hunan to press for his release. Alan said: ''I telephoned and faxed Thomas Foley and Slade Gordon and asked them to intervene personally, or ask the US embassy in Beijing to intervene, and I am notifying the state department first thing Monday morning.'' He said he hoped his father's American citizenship would encourage PSB officials to release him. ''The issue of human rights in China and the US notification that they were in hot water for selling missiles to Pakistan may have an effect because my father is a US citizen. ''Hopefully they will see he is a US passport-holder and won't harm him, but he could be held in detention without any legal proceedings indefinitely. China is not exactly known for its legal system, or for adhering to its statutory law.'' Alan said his father was taken by force in a raid on a hotel room where he was signing a renegotiated contract with the Hunan Arts and Crafts Import and Export Company. ''The original contract was a US$200,000 [HK$1.55 million] investment, and all the payments were supposed to be made by May. By April, they had wired US$165,000, so they didn't fulfil their promise, and then they demanded the US$165,000 back, in effect nullifying the contract. ''Dad thought that rather than ignoring them, what we should do is try to help them out, so he proposed a new contract, whereby the US$165,000 would be considered as debt, and we would pay them back over a series of months. ''This was apparently agreed and signed, but upon signing, PSB agents swarmed into the room, and forcibly took my father's passport and detained him. ''We are not clear why it took place. I can only speculate they feel we were out to swindle them.''