Some burgers made by meat processor Rangeland Foods for the UK wholesale and catering trade contained up to 30% horse, new tests have revealed.
The company said that it sourced the contaminated meat from Poland - the second batch from the country that has tested positive for equine DNA at the Monaghan factory.
However, food safety and agriculture chiefs have given Rangeland the all-clear to resume production on condition that it only use Irish sourced beef.
Rangeland said the burgers date back to production in September. "Rangeland Foods has since taken the decision to withdraw all of their hitherto untested produce made from meat of Polish origin from the food chain, and that process is under way," the company said.
According to tests on samples of batches made at the Castleblayney factory and supplied to the UK wholesale and catering trade, some burgers were found to have 5-30% equine DNA.
The company said a small number of cases had tested positive. It said that the 9,200 withdrawn 4oz Rangeburgers were made to a specification for EU beef from EU-approved suppliers.
Rangeland said that it had supplied two UK food service providers.
Rangeburgers have also been sold to the catering and wholesale sectors in Ireland, Spain, France, Germany and the Netherlands, the Food Safety Authority of Ireland (FSAI) said. The FSAI said Rangeland had notified companies it trades with and a withdrawal is taking place.
"As is the protocol in food withdrawals, if these suppliers have subsequently traded these products onwards to other food businesses, they are compelled to notify them to ensure that a swift withdrawal is undertaken across the market," the agency said.
A food alert has been issued by the FSAI to the European Commission via a rapid alert system for food and feed to stop use of the burgers.