The fast food chain said sorry to customers as it confirmed it was cutting ties with Silvercrest, the food processing plant that supplied contaminated burgers to UK supermarkets.
Burger King said its own tests for equine DNA in its burgers had come back negative and that four samples from the Silvercrest plant that did test positive were from a product that did not make it into restaurants.
The Miami-based chain said the failure to deliver 100% British and Irish beef patties was a violation of contracts.
The UK newspaper ads include a statement from Diego Beamonte, Burger King Corporation's vice president for global quality, who said: "While the Food Safety Authority of Ireland has stated that this is not a food safety issue, we are deeply troubled by the findings of our investigation and apologise to our guests, who trust us to source only the highest quality 100% beef burgers.
"Our supplier has failed us and in turn we have failed you. We are committed to ensuring that this does not happen again."
The Irish authorities said that their investigations had traced filler product used in the burger processing facility to a supplier in Poland.
It contained a mixture of beef and horse off-cuts.
Experts from the Food Standards Agency (FSA) yesterday told the Commons Environment Committee that they could not be sure whether the contaminated burgers were being sold for more than a year.
Bosses at the Food Safety Authority of Ireland (FSAI), who identified and publicised the controversy, and Department of Agriculture chiefs have yet to be questioned at a similar level in Dublin.
At least 10 million burgers were put into storage following the scandal. Silvercrest's parent company ABP Food Group initially said they would be destroyed.
Silvercrest had a contract to supply Burger King in the UK, Ireland and Denmark. It is understood the deals with the fast food chain and Tesco (Other OTC: TSCDY - news) were worth in the region of £39m.
The Ballybay processing factory, closed since the scandal broke two weeks ago, employed 112 people.
Burger King said it had carried out its own internal investigation including scientific tests, inspection of the Silvercrest facility and scrutiny of traceability records over the last fortnight.
It has been using approved suppliers from Germany and Italy as a precaution since.
Burger King's apology came after Aldi suspended its contract with beefburger supplier Dalepak, having found small traces of horsemeat DNA in its products.
The supermarket withdrew three beefburger lines earlier this month after traces of pig meat and horsemeat were discovered, and launched an investigation.
"Aldi UK's customers are our absolute priority," a spokesman said. "This is why we immediately withdrew these products until such a time that we could verify that there was no risk to our customers.
"We are deeply angry and feel let down by our supplier and we are pursuing more tests until we are certain that we understand how the production line was contaminated."
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