(IDEX Online) - A gang swapped $5.3m of diamonds for a bag of worthless pebbles in an audacious sleight-of-hand heist at a top London jeweler.Detectives said the astonishing raid was like something from the Ocean's Eleven movie franchise, starring George Clooney and Brad Pitt.The thieves posed as wealthy Russian businessmen to dupe luxury jeweler Boodles - founded in 1798 - out of seven stones, in March 2016, Southwark Crown Court, in London, heard as a second gang member was jailed.The most valuable stone at the Mayfair store (pictured) was a 20ct heart-shaped jewel worth $2.8m. The gang also got away with a three-carat pear-shape fancy intense purple pink diamond worth $1.4m, and a six-carat Ashoka-cut diamond.The elaborate sting centred on a switch, in which a woman posing as Anna, a gemologist managed to exchange the diamonds for pebbles after weighing and examining them, according to Britsih newspaper reports. She put a zipped bag containing the diamonds into her handbag for a moment, while the manager was distracted.She was challenged by Boodles' own gemologist. and obligingly withdrew an identical bag - containing nothing more than pebbles - which went unchecked until the gang had left.The heist has been described as the largest-value single incident of shoplifting in British criminal history.Mickael Janovic, 27, a French national, was jailed for three years and eight months for conspiracy to steal.Christophe Stankovic was extradited from France and jailed in 2016 for his part in the crime. The remaining four gang members - and the diamonds - have not been seen since the raid.Pic credit: Google Street View