The metal often used as a gauge of economic health also suffered after inventories in London Metal Exchange-registered warehouses jumped by a third overnight, providing a boost to supplies in LME depots after months of erosion.
The World Health Organisation warned on Tuesday that the new coronavirus was likely to spread to other parts of China and possibly other countries in the coming days as the death toll in China rose to six.
China is also preparing for its week-long Lunar New Year holiday, starting on Jan. 24, with many traders closing their positions before taking time off and millions of people travelling, stoking fears of a wider spread of the virus.
"The sector is taking a bit of a tumble. Even though it's (virus) on a relatively small scale right now, it just hits confidence, having a dampening impact on the otherwise risk-on climate that's we've had so far this year," Ole Hansen, head of commodity strategy at Saxo Bank in Copenhagen.
Funds are net long of the CME copper contract for the first time in nine months and the speculative net long position on the LME had grown to 15pc of open interest as of Friday, according to estimates by broker Marex Spectron.
"A lot of these recently established longs are potentially getting close to being out of pocket and that's adding to the selling pressure," Hansen said.
Benchmark LME copper had slid 1.6pc to $6,161.50 a tonne by 1120 GMT, the biggest one-day loss since Oct. 31. It earlier touched $6,150, the weakest level since Jan. 8.
The most-active copper contract on the Shanghai Futures Exchange closed down 1.4pc at a six-week low of 48,420 yuan a tonne.
COPPER STOCKS: LME copper inventories <MCUSTX-TOTAL> surged by 38,700 tonnes to 162,925 tonnes, daily LME data showed. Until the big inflows, stocks had shed 63pc from their peak last August.
COPPER DEFICIT: The global world refined copper market showed a deficit of 33,000 tonnes in October, down from 89,000 tonnes in September, data showed.
ZINC SPREAD: The premium of LME cash zinc to the three month contract <CMZN0-3> has increased to $22.25 a tonne, the highest since Nov. 29 and compared to a discount of $3.50 on Dec. 11. This indicates tighter availability of LME supplies.
OTHER PRICES: LME aluminium added 0.6pc to $1,823.50 a tonne, zinc fell 0.4pc to $2,435, nickel shed 1.2pc to $13,855, lead added 0.2pc to $1,965.50 while tin lost 0.8pc to $17,715 after earlier rising to $17,970, the strongest since July last year.