London jeweler sues in Manhattan for return of 16-carat diamond stolen in 2007

A massive yellow diamond swiped in a brazen $20 million London robbery landed in a Hong Kong pawn shop — and its owners are suing for the long-missing bauble’s return.

The 16.28-carat diamond was stolen in 2007 by a pair of armed and upscale bandits who fled with their loot in a $250,000 Bentley Continental Flying Spur, British authorities said.

In court papers, Graff Diamonds Ltd. demanded immediate return of the purloined diamond, declaring it was “the only rightful owner” — and not the Yau On Pawnshop.

“Because the diamond was stolen from Graff, no party in the chain of custody subsequently possessing the diamond, including Yau, has good title,” claimed the documents filed in Manhattan state court.

The stunning sparkler is now in the hands of the Gemological Institute of America on Fifth Ave., where it was brought by the pawn shop owners to certify its worth.

Michael Bono, the attorney for Graff, declined further comment on the case.

“It is my client's policy not to comment on matters in litigation,” he said.

But the court papers indicate the fight began nearly a year ago, with Graff first demanding the gem giveback on Jan. 26, 2011.

The diamond was part of a massive heist on July 5, 2007, when a well-dressed pair of thieves entered Graff’s west London branch posting as customers.

The duo, after chatting up the staff, pulled handguns and swiped an assortment of diamonds, rings, necklaces, pendants and other valuables. One of the stolen items was a $2 million necklace.

The pair then calmly climbed inside their luxury car and drove away — one clad in a cream-colored suit, the other sporting a dark blazer and a Panama hat.

The GIA — which had inspected the diamond before it was stolen — notified Graff when the pawn shop turned it over for evaluation.

“Yau is not a good-faith purchaser,” the court papers said. “Yau was and/or should have been aware that the diamond was sold to it in violation of the rights of the true owner.”