A plot to pass horsemeat off as beef fell apart after horse identification chips were found in the meat by inspectors, a court has been told.
Andronicos Sideras, 54, has been accused of deliberately mixing up the meats before they were sold in 2012.
Mr Sideras was one of the owners of meat company and sausage manufacturer Dinos & Sons.
The businessman, from Southgate, north London, denies conspiracy to defraud between 1 January and 30 November 2012.
Prosecutor Jonathan Polnay said alarm bells were raised after Dinos “messed things up” when assembling an order.
A surprise inspection was triggered when the wrong size of shipment was sent to a company called Rangeland in Newry, Northern Ireland, in 2012, Inner London Crown Court was told.
The 12-pallet load was analysed and four of them contained horse.
Mr Polnay said: “Some of them were found to contain significant amounts of horsemeat; roughly about a third contained horse.”
It is alleged Mr Sideras mixed meat in this way before it was sold on to manufacturers making products for “a vast range of well-known companies”.
Mr Sideras’s fingerprints were found on “fake” labels, the court heard.
Mr Polnay added: “The final piece of the jigsaw is that when the meat was analysed, three horse ID chips were found in some of it.”
The chips were roughly the size of a 1cm grain of rice – two of which were Polish and one Irish.
It is alleged Danish-owned company Flexi Foods would buy horsemeat and beef from suppliers across Europe and then deliver to Dinos & Sons in Tottenham, north London.
Mr Polnay said the fraud could not have worked or taken place without the “connivance” of Mr Sideras.
He said: “The meticulous records kept by FlexiFoods caused their undoing. They also provide compelling evidence of the guilt of this defendant.”
He told the court that two men, Ulrik Nielsen, 58, the owner of FlexiFoods, and his “right-hand man”, Alex Beech, 44, have already pleaded guilty to the same charge.
The trial continues.