Notes from Brian on the Stanley Camp Discussion List:
George Lyon-Mackenzie was one of the bankers kept out of camp to liquidate the HKSBC. He was too sick ever to be interned, but he assiduously smuggled money etc into Stanley, including from Rosary Hill.
He was previously in charge of the HKSBC Bank in Harbin - this 1940 article sees the city from the viewpoint of his wife and daughter:
http://trove.nla.gov.au/ndp/del/article/17650945?searchTerm=MACLEAY
He's on the British Army Aid Group list of bankers in the Sun Wah Hotel, but when this group were sent to Stanley in July 1943 he was too ill to go so was sent to the French Hospital. He wasn't expected to recover, but in fact became well enough to go to Rosary Hill to convalesce. Towards the end of the war, he went into 'the Church House' - I don't know where this was, but I'd guess that he was still too ill to go to Macao.
'From each of these locations Lyon-Mackenzie organised supplies for the internees in Stanley' (Frank King).
At the end of the war, although still ill, he took over the HKSBC Bank, gaining control of its books and preparing for the arrival of his colleagues from Stanley.
The only other thing I know about him, is that although he was obviously highly courageous and committed to relief work, he felt that Charles Hyde, the most active of the bankers in all forms of illegal activity, was going too far, and he tried unsuccessfully to get David Edmondston, number 2 in the hierarchy, to rein him in. Hyde was eventually executed and Edmondston died in prison of malnutrition and medical neglect. I think this clash highlights the problem faced by all of those kept uninterned: how to carry out works of relief and resistance as safely and effectively as possible?