Security camera footage released by police shows two men in crisp suits entering Graff Diamonds' flagship store last Thursday afternoon. It was the third time a Graff store in London had been targeted in a high-profile raid in the past six years.
The men stole dozens of high-end rings, bracelets, necklaces and watches worth £40 million ($NZ100m), and fired two gunshots into the ground as they escaped in a series of getaway cars, police said. No one was hurt.
It was among the biggest heists in British history - far outstripping the 1963 Great Train Robbery in which £2 million was stolen.
Last week's theft, however, was topped by the 2006 robbery of £53 million in cash from a security company depot in southern England, and was rivalled by the 1987 theft of an estimated £40 million from the Knightsbridge Safe Deposit Centre in London.
Police declined to rank Thursday's robbery, saying only that it was one of the country's biggest. Items stolen included a pair of white diamond double hoop earrings, a flowing flower necklace with yellow diamond petals, a platinum white Marquise diamond ring and a Chronograff watch, police said.
Graff's store, a classical stucco and stone town house in London's jewellery district, has been targeted by thieves in the past.
The same store lost jewellery worth £23 million in 2003 when it was robbed by jewel thief Nebojsa Denic, a Kosovan Serb and a member of the notorious gang of Balkan robbers known as "the Pink Panthers." Denic was caught and sentenced to 15 years in prison.
In 2007, another smartly dressed pair was chauffeured to the store's Sloane Street branch in a Bentley Continental Flying Spur. They whipped out handguns and made off with £10 million worth of gems.
Graff Diamonds declined to give details beyond the police statement.
