Conmen studied Who's Who in Hong Kong to target wealthy people they could dupe into buying fake wartime buried treasure, police said yesterday. Several wealthy people were contacted and asked if they were interested in buying gold or coins and banknotes used in the early Nationalist era of the 1910s. The gold was fake and they would have been cheated, although no one took the bait, said Detective Senior Inspector Cheng Wai-ming of Yau Tsim district crime squad. Police arrested four mainlanders and a local resident suspected in the scam and seized 936 fake gold nuggets and buddhas and 111 coins and banknotes in raids on a Yau Ma Tei hotel room and Kwun Tong flat. The 1995 edition of Who's Who in Hong Kong and a forged will claiming a wealthy mainlander had buried the valuables were also found. Last night the five suspects were being detained at Tsim Sha Tsui police station.