A Sainsbury's IT manager who stole millions of Nectar points after finding a "loophole" in the system was jailed for 20 months yesterday.
James Stevenson, 45, set up accounts for the reward card scheme using false names and credited them with 81,000 worth of the points.
The father-of-two, of Muswell Hill, north London, admitted using some of them to purchase 8,120 worth of goods from the store.
Stevenson, an IT team leader who worked at the supermarket's headquarters in Holborn, central London, pleaded guilty to fraud and theft at a previous hearing.
The Old Bailey heard that he had worked for the company for 20 years and had access to the computer systems which operate the Nectar card.
He added points to at least 18 accounts that he had created, using the names of DJs, in two spells, between November 2002 and May 2003, and from October 2007 to December 2009.
The court heard he would go on test runs in the supermarket, using points to buy one item at first, then when it passed unnoticed going back and filling a trolley.
Edward McKiernan, prosecuting, said that when Stevenson's fraud was discovered by Sainsbury's he told them he had "discovered a loophole in the system".
Mr McKiernan said: "There wasn't a proper check in place. He was a trusted employee so no-one was looking over his shoulder."
Judge Peter Thornton told Stevenson: "Your motive was clearly greed. This was a carefully-planned, well-worked fraud on Sainsbury's."
The defendant was ordered to repay 8,120 to the supermarket.