G'day, I lifted this from Wikipedia:
"In conjunction with its military campaign in World War II, the Empire of Japan invaded Hong Kong on 8 December 1941. The Battle of Hong Kong ended with British and Canadian defenders surrendering control of the colony to Japan on 25 December. During the Japanese occupation, civilians suffered widespread food shortages, rationing, and hyper-inflation due to forced exchange of currency for military notes. Hong Kong lost more than half of its population in the period between the invasion and Japan's surrender in 1945, when the United Kingdom resumed control of the colony." ...
"In 1934, the last 1 cent coins were issued, but the last minting was 1941. These were not issued because of the Second World War."
Peter