THE Director of Immigration had acted outside his power to impugn a travel document issued to a businessman by the Chinese Government, the High Court heard yesterday. The decision to refuse Tsui Siu-wai permission to land and stay in Hong Kong on the unsupported allegation that his one-way permit had been unlawfully obtained was absurd and unreasonable, it was submitted. Asking Mr Justice Patrick Chan to overturn the decision to refuse him entry and to detain him pending his removal from Hong Kong, Defence counsel Martin Lee QC also contended that the director had no jurisdiction to declare a document issued by another sovereignty null and void. The court heard that Tsui, 35, was a Chinese national and was issued with a one-way exit permit in Hunan in August last year. He landed in the territory on August 7 last year. He was granted a Hong Kong identity card and frequently travelled between China and Hong Kong. However, counsel said, when Tsui entered Hong Kong from Lowu again on June 16 he was refused entry and was detained overnight before being granted bail. He was informed by the Director of Immigration that the reason for the refusal was that according to Chinese authority, the one-way permit he held was unlawfully issued. The hearing continues today.