An 18th Century Chinese imperial seal has been sold for a record €21m (£18m, $22m) - more than 20 times its estimated price, according to BBC.

The sale, to an unnamed Chinese collector, took place in Paris on Wednesday after a heated bidding war, Drouot auction house said.

The palm-sized seal is made of red and white steatite, a type of mineral rock.

It was one of hundreds owned by Emperor Qianlong, one of the longest serving Chinese emperors.

The previous record set for an auctioned seal was €14m in 2011.