Dutch food safety authorities have ordered the withdrawal of about 50,000 tonnes of beef from sale over concerns it might contain horsemeat.
The Netherlands Food and Consumer Product Safety Authority (NVWA) said in a statement it had told more than 130 Dutch meat-processing firms to trace the meat and withdraw it.
All of the meat came from two Dutch wholesalers.
The wholesalers involved were Wiljo Import en Export BV and Vleesgroothandel Willy Selten BV.
"It might contain traces of horsemeat, but we don't know for certain at the moment if this is the case," said a spokeswoman for the authority.
The Food Safety Authority has confirmed an Irish supplier imported meat from one of the Dutch companies.
The Department of Agriculture has said it is following up on the matter.
Inspectors examining Willy Selten's records had found that the origin of the meat it supplied was unclear, the NVWA said.
The authority said that meant it was impossible to confirm slaughterhouses had been acting according to procedure.
It said it did not know where the meat had ended up, but it could have been used in frozen products.
"The buyers have probably already processed the meat and sold it on," it said in a statement.
"They, in turn, are obliged to inform their own customers."
About 370 companies in other European countries have also bought the meat, and the Dutch food authority has warned foreign counterparts about the recall via a European rapid alert system, it said.
It said there was no immediate suggestion of any danger to human health.
In January, tests in Ireland revealed some beef products contained horsemeat, triggering recalls of ready-made meals in several countries and damaging confidence in Europe's vast and complex food industry.