Imports via Hong Kong to China, the world's top consumer of the metal, slipped to 19.22 tonnes in December from 37.871 tonnes in November, according to data from the Hong Kong Census and Statistics Department.

Total gold imports via Hong Kong plunged nearly 42 percent to 24.149 tonnes last month, compared with 42.104 tonnes in November.

China already imported close to 200 more tonnes of gold in 2018, said Samson Li, a Hong Kong-based senior precious metals analyst, Refinitiv GFMS.

"The PBOC (People's Bank of China) probably noticed this, and was reluctant in granting import licenses in December."

In November, China's net gold imports through Hong Kong surged 28 percent from the previous month to their highest since July.

Spot gold rose about 5 percent in December, and is up 1.4 percent so far this month.

While investment demand did pick up as prices rose, jewellery consumption, which makes up a chunk of demand in China, "lost steam toward the end of the year and fell on a year-on-year basis," Li added.

China does not provide trade data on gold, so the Hong Kong figures serve as a proxy for flows to the mainland.

The Hong Kong data, however, might not provide a full picture of Chinese purchases because gold is also imported via Shanghai and Beijing.