Mare's the beef?

Burger King announced Thursday that it had terminated its relationship with European supplier Silvercrest Foods after finding traces of horse meat in beef patties at a Silvercrest facility.

Silvercrest provided beef for Burger King restaurants in the United Kingdom, Ireland and Denmark. Burger King said that while samples of beef from restaurants in these countries showed no evidence of contamination, four samples from a Silvercrest plant in Ireland showed "very small trace levels of equine DNA."

Burger King (BKW) said the tainted product was never sold in restaurants, and appeared to have originated from a sub-contracted supplier in Poland.

"[W]e are deeply troubled by the findings of our investigation and apologize to our guests, who trust us to source only the highest quality 100% beef burgers," Burger King's vice president for global quality, Diego Beamonte, said in a statement.

Burger King spokeswoman Kristen Hauser said in an email that Burger King's U.S. restaurants don't use meat from Silvercrest.

"We have stringent and overlapping controls to ensure that the products we sell to our customers meet our strict quality standards," she said.

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Ireland's Food Safety Authority said earlier this month that the products in question did not pose a safety risk. Ireland's Department of Agriculture said its own tests of the Polish meat imported by Silvercrest for burger production showed that it was roughly 4% horse.

U.K.-based grocery chain Tesco also announced earlier this month that it had discovered horse DNA in beef products sourced from Silvercrest, and had terminated its relationship with the supplier.

Paul Finnerty, CEO of Silvercrest parent ABP Food Group, said in a statement that the company had implemented a "total management change" at the facility where the horse meat was discovered, and had established "comprehensive DNA testing procedures" to address the issue going forward.

"We are proud of our excellent reputation for quality and service throughout Europe and are determined not to allow the Silvercrest incident overshadow what is a great business," Finnerty said.