[TOKYO] Japanese police were on the hunt on Friday for a stolen diamond worth more than US$1.8 million after the pricey piece was discovered missing from a jewellery trade show outside Tokyo.

"The diamond stolen on Thursday was valued at 200 million yen. We believe it was stolen from a display case," a police spokesman told AFP.

The 50-carat loose diamond was on display at a three-day show in Yokohama city where companies from Japan, Russia, China and elsewhere are showcasing their sparkly wares.

According to public broadcaster NHK, the theft was noticed by an employee who noticed the item was missing and realised that the display case was unlocked.

The item, belonging to a Japanese firm, appeared to be the only piece taken from the show, which was not halted over the theft and wraps up on Friday.

AFP