A mainlander who entered Hong Kong illegally in 1970 was unlawfully given right of abode after the Registration of Persons Tribunal exceeded its powers, according to a High Court writ filed yesterday. The writ, taken out by the Commissioner for Registration, states the tribunal made a 'material and decisive mistake of law' in finding Wong Hi-kwong, 65, had right of abode. The commissioner is seeking a declaration that the tribunal's finding was unlawful and for it to be quashed. He is also seeking a judicial review on the matter. Mr Wong entered Hong Kong illegally from the mainland on September 3, 1970, and was granted permission to remain unconditionally by the immigration director 15 days later. On January 22, 1971, Mr Wong was issued a Hong Kong identity card. A year later he applied for a Hong Kong Certificate of Identity to emigrate to Canada, which he did in 1972. But Mr Wong returned to Hong Kong on January 17, 1992, and was allowed to remain as a visitor during various visits. In December 1994, he claimed he had right of abode in Hong Kong because he used to live in Hong Kong. His request was denied. The writ states Mr Wong had overstayed from August 27, 1995 - the last extension on his visitor's visa - until now. He then applied for a Hong Kong permanent identity card on February 12 last year but was refused by the commissioner on the same day. The writ arises from Mr Wong's appeal to the Registration of Persons Tribunal finding against the commissioner's refusal and its decision to grant Mr Wong right of abode. The tribunal found that Chinese residents granted unconditional stay in Hong Kong before April 1, 1972, did not have to reside continually in Hong Kong for seven years. After April 1, 1972, all immigrants had to apply for a Hong Kong ID card and set out new requirements for the right to land. The tribunal concluded: 'For this reason, this tribunal believes that when [Mr Wong] landed in Hong Kong on 17 January 1992, he had the right to land.' But the writ claims the law granting Mr Wong unconditional stay in 1970 conferred no right to land then or on subsequent return visits to Hong Kong. 'It is clear that immigrants from mainland China were aliens and subject to immigration control.'