Seven premises in five counties have been searched by gardaí investigating suspected contamination of horse meat for export.
The National Bureau of Criminal Investigation is investigating if meat from horses that should not have been processed for consumption has been processed for human consumption.
Planned searches were carried out at locations in counties Roscommon, Leitrim, Sligo, Westmeath and Kilkenny by gardaí along with officials from the Department of Agriculture and the Food Safety Authority of Ireland.
Detectives suspect that meat from horses that should have been destroyed and not used for human consumption may have been processed and exported to Europe.
They do not believe that any potentially contaminated horse meat has been sold in this country.
The meat from horses that have been injected with hormones or medicines, who have been ill or who are old is not to be used for human meat products and is often worthless and there can be a cost to have these animals destroyed.
However, animals whose meat can be used for human consumption have a value and can be sold.
Detectives will try to establish if individuals have been complicit in such activity or have been duped.
The seven premises being searched include farms and commercial premises connected with the food industry.