HONG KONG residents who immigrated from the mainland since the 1980s are closely scrutinised when they apply for Taiwan visas, Taipei's de facto representative in the SAR said yesterday. 'It is highly possible that Beijing sent people to Hong Kong during the '80s and afterwards, and they should be treated differently,' said Cheng An-kuo, managing director of the Chung Hwa Travel Service. It is the first time a Taiwan official has publicly acknowledged that Taipei is worried about Chinese agents infiltrating Taiwan through Hong Kong. But speaking in the SAR, Mr Cheng said other Hong Kong visitors should face few problems. 'Those born in Hong Kong and who came before the 80s, with very few exceptions, have no problem.'