The Irish Food Standards Agency is now considering testing burger restaurants - so far they have only tested retailers.
I have checked the UK Food Standards Agency archives and found that in 2001 they worked with 22 Local Authorities to test frozen chicken breast. Of 68 samples taken, two had pork DNA.
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?