EU Health Commissioner Mr David Byrne has asked the Irish, Belgian, Dutch and German governments for an explanation as to how some supplies of pork came to be tainted with illegal growth hormones, a European Commission spokesman said.
The spokeswoman said the case has triggered the Commission's rapid alert system for food problems.
The Belgian authorities last week discovered what they described as "materials" of Irish origin at the Belgian company Bioland, which is suspected of having supplied hormone-laced pig fodder to Dutch farms.
Separately, the German agriculture ministry said Germany has imported around 7,500 hormone-tainted pigs from the Netherlands since May.
At issue is the MPA growth hormone, which the Commission says can cause sterility in humans if ingested over a long period of time.
AFP