Beef products sold at various retail outlets in Ireland have been found to contain horse and pig DNA, The Food Safety Authority of Ireland (FSAI) announced Tuesday.

The agency conducted tests on 27 beef burger products and found that at least 10 of them had horse DNA in them and 23 had presence of pig DNA.

All other beef products like pies, lasagna and salami tested positive for pig DNA, but not horse DNA, the agency said. Traces of horse DNA were found in raw meat imported from Netherlands and Spain.

Though most products had just traces of horse meat, one product sold at Tesco contained horsemeat that accounted nearly 29 percent of the total beef product.

"Whilst, there is a plausible explanation for the presence of pig DNA in these products due to the fact that meat from different animals is processed in the same meat plants, there is no clear explanation at this time for the presence of horse DNA in products emanating from meat plants that do not use horsemeat in their production process," Prof. Alan Reilly, Chief Executive, FSAI.

Retailers selling the beef products said they are now removing the products that have been found to contain horse DNA. One manufacturer, Silvercrest Foods, told FSAI that it is replacing all the implicated products.

 "In Ireland, it is not in our culture to eat horsemeat and therefore, we do not expect to find it in a burger. Likewise, for some religious groups or people who abstain from eating pig meat, the presence of traces of pig DNA is unacceptable," Reilly said in a news release from FSAI.