Seven samples of raw ingredients were tested by the Irish Department of Agriculture, including one sourced from another European country which tested positive.
All ingredients in the production of burgers sourced from Irish suppliers tested negative for horse DNA, the department said.
The positive samples will now be analysed further in Germany with a view to quantifying the percentage of horse DNA present.
Thirteen samples of finished burgers were tested for the presence of equine DNA. Nine have tested positive for traces of equine DNA and another four have tested negative. The minister and the FSAI have repeated their clear statement that there is no concern from a food safety perspective.
The horsemeat scandal demonstrates how long and complicated the food chain we all depend on is. Regulating our food supply is expensive.
Some of the best, and worst, jokes and gags from Twitter users discussing the discovery of horse DNA in some supermarket beef burgers.
We've seen the jokes on Twitter but the discovery of horse and pig DNA in beefburgers poses a serious question; where did it come from?