Sinclair was born in Thornton, Wellington, New Zealand, to 16-year-old Margaret Hocking of Cornish extraction and a mixed Polynesian father who left, never to return, when he was three.
[1]: 35–41 At 14, he was deeply affected by Edgar Snow's glowing 1937 account of the Chinese Communist Party, Red Star Over China, later rating it the book that most influenced his outlook.
Having left New Zealand in 1961, he lucked into his first job in Australia as the sole employee (and editor) of the south Queensland tourist-targeted rag, the Surfers Paradise Guide, and, by 1962, he was working as a reporter at Brisbane's The Telegraph.
[2] Four days before his death, he had attended a book signing at Hong Kong's Foreign Correspondents' Club - an event even attended by Hong Kong Chief Executive Donald Tsang who he counted among his many friends, including Singapore's Prime Minister Lee Kwan Yew and billionaire transport magnate Sir Tang Shiu-kin among his friends.
[1]: 87, 90 A celebration of his life was held at the Hong Kong Police Officers' Club on 7 January 2008 attended by 300 government officials, close friends and colleagues.