Two held over 40m Graff gem heist

The police said the pair were arrested on Wednesday, but issued no details for "operational reasons".

In the audacious raid, two weeks ago, two men wearing suits posed as clients to get past a security guard. Once inside the New Bond Street shop they pulled out handguns, threatened staff and grabbed luxury rings, bracelets, necklaces and watches.

Scotland Yard released CCTV footage showing the duo leaving the jewellers. They fired at a security guard before getting into a blue BMW, passing a package to a motorcyclist before crashing into a taxi nearby. They fired a second shot as members of the public tried to intervene, before getting into a silver Mercedes and then a people carrier.

The first suspect was described as white, about 30, with a slim build, dark hair with a well-combed side parting, light stubble on his face and between 5ft 10in and 6ft tall. The second was described as black, also in his 30s, 6ft tall, heavier built than the first suspect, and with very short hair. At least two other men were acting as getaway drivers in three cars, police thought.

It was reported that the robbers had asked make-up artists to age them 30 years, but abandoned the plan because it would have taken too long. DNA tests were carried out on masks that the robbers tried on in the studio but did not use. The jewels stolen were worth £40m, dwarfing Britain's previous biggest diamond robbery in 2003, when items worth £23m were stolen, also from Graff's.

Police also released images of some of the 43 items of stolen jewellery, including a pair of white round diamond double-hoop earrings, a yellow diamond flower necklace, a platinum white Marquise diamond ring and others.