WARSAW, Poland (AP) -- One of Poland's top veterinarians said Thursday that traces of horse-meat DNA have been found in beef samples taken from three meat processors -- the first acknowledgement that the country could be a source of the horse meat that fraudulently ended up in processed meat products sold as beef across Europe.
Deputy National Veterinarian Janusz Zwiazek said the DNA was found in three samples out of 121 tested. They came from cold storage at processing plants in central Poland. The meat arrived there from various suppliers in Poland and abroad, including from the Netherlands, Zwiazek told The Associated Press.
Dutch authorities also announced Thursday that their large-scale testing program has uncovered horse meat in two samples out of 370 tests it has carried out since Europe's horse meat scandal erupted.
The country's Food and Wares Authority said it found horse DNA in a batch of beef cuttings and in a meatball labeled as containing only beef and pork at a meat processor and a frozen storage center.
The authority did not release the names of the companies where it found the horse meat traces.
In Greece, authorities said they detected traces of horse meat in salami labeled as containing beef that was imported from the Netherlands, and in frozen kebabs packaged locally. It was unclear whether the kebab meat was locally produced or imported, and food safety authorities were not available for comment.
Greece first detected horse DNA in meat labeled as beef on Wednesday, in frozen meat from Romania.
Polish authorities said some 80 more samples are to be tested, and separate tests are needed to determine the proportion of horse meat.
All three contamination cases have been reported to the prosecutors, Zwiazek said.
"I want to find the culprit, or culprits," he said.
Horse meat has recently been found mixed into beef dishes sold across Europe, including in frozen supermarket meals. It also has been found in meals served at restaurants, schools and hospitals. Authorities say it is a case of fraudulent labeling but does not pose a health risk.
The scandal has drawn attention to the complex and murky trade in meat before it reaches the consumer.
Mike Corder contributed from Amsterdam and Nicholas Paphitis from Athens.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.