China's unwrought copper imports rose 9.1% in December from the previous month to their highest since March 2016, customs data showed on Tuesday, as improving industrial activity and dwindling scrap metal supply lifted demand.

Imports of unwrought copper, including anode, refined and semi-finished copper products into China, the world's biggest copper consumer, stood at 527,000 tonnes last month, data from the General Administration of Customs showed.

That compared with 483,000 tonnes in November, itself a 13-month high, and was up 22.8% from December last year.