A businessman has been found guilty of being part of a near-£200,000 conspiracy to pass off 30 tonnes of horsemeat as beef, much of which went on to enter the food chain.
Andronicos Sideras, 55, one of the owners of meat manufacturer Dinos & Sons, mixed the meats together before it was sold on to other firms in a plot which deceived consumers and food processors.
The jury of five men and seven women at Inner London Crown Court took 10 hours and 17 minutes to deliver a majority guilty verdict following a four-week trial.
Ulrik Nielsen, 58, owner of FlexiFoods, and his "right-hand man", Alex Beech, 44, had already pleaded guilty to their part in the plot.
The court heard how Danish-owned company FlexiFoods would buy horsemeat and beef from suppliers across Europe and have it delivered to Dinos in Tottenham, north London.
Labels and paperwork were fabricated to make the mixed meat appear like pure beef, before it was sold on to food manufacturers making products for a "vast range of well-known companies", prosecutor Jonathan Polnay told the trial.
Dinos is a provider for several Greek restaurants, supermarkets and other producers.
Mr Polnay told the court during the trial that the plot was "motivated by greed" and said it could not have happened without the "connivance" of Sideras.
At the time, beef could be sold at a wholesale price of three euros per kilogram, while horsemeat was cheaper at two euros per kilogram.
The plot unravelled in September 2012 when one of the loads ended up in a Freeza Meat store in Newry, Northern Ireland, and a surprise health inspection by Newry and Mourne District Council later revealed a third of the pallets contained horsemeat.
Horse ID chips, roughly the size of a grain of rice, were also found in the meat.
They belonged to two horses named Trak and Wiktor from the Lodz region of Poland, and a third Irish Hunter horse called Carnesella Lady, from rural county Galway.
The horses had all been owned by farmers who sold them on to parties who police said failed to re-register the animals, meaning they could only be traced back to their original owners.
The animals had not been sold for slaughter and there is no suggestion the farmers had any involvement in the conspiracy, police said.
Sideras, of Southgate, north London, had claimed that he was not part of the conspiracy and had only stored the product for FlexiFoods.
But the jury found him guilty of one count of conspiracy to defraud between January 1 and November 30 2012, the same charge to which Nielsen and Beech had earlier pleaded guilty.
Dinos had a number of infringements for mislabelling products between 2007 and 2012.
Sideras was released on bail ahead of sentencing alongside Nielsen, of Gentofte in Denmark, and Beech, from Sutton-on-Hull, on Monday at the same court.
Detective Constable Stephen Briars of City of London Police, who were asked by the Food Standards Agency to carry out an investigation, said the overall face value of the fraud was £177,000 but the true cost is likely to have run into millions of pounds.
He said: "The knock-on effect is incalculable millions."
Police said the conspiracy involved 30 tonnes of horsemeat, 20 of which were destined for the food chain and 10 of which were sent to a cold store elsewhere.
Mr Briars said the majority of the horsemeat did go on to enter the food chain and undoubtedly had a ripple effect, contaminating many more meat products.
He said: "The reason that the relatively small amount of horsemeat in comparison to the beef supplied to companies has had such a big effect on so many different products is because, for example, one tonne of raw material is actually distributed amongst numerous production runs because of the need to maintain consistency of the finished product.
"Therefore one tonne of horsemeat could appear in multiple finished products due to how the factories work."
Nina Montalbano, from the Crown Prosecution Service, said all three men knew full well what they were doing.
She said: "These men, motivated by greed, knowingly sold horsemeat to manufacturers so they could increase their profits.
"Faced with the evidence put forward by the CPS Nielsen and Ostler-Beech pleaded guilty, whereas Sideras was convicted by a jury.
"All three defendants knew full well this meat would enter the food chain through a number of leading supermarkets but continued their fraud with blatant disregard for the public's right to know what is in their food."