Gardaí have raided farms, houses and commercial premises as part of an investigation into horse meat deemed unfit for human consumption entering the food chain in Ireland.

The investigation is being led by the Garda National Bureau of Criminal Investigation, the force’s serious crimes squad. The Criminal Assets Bureau is also involved as the suspected fraud is regarded as very lucrative for the key players.

While horse meat is not widely consumed in Ireland there is a larger international market that Irish meat is exported to.

Gardaí believe some horses that should have been slaughtered at the end of their lives, which were not fit for human consumption, have effectively been smuggled into the food chain. Sources stressed that some people or businesses at the centre of the searches may have been victims of the fraudsters rather than being engaged in any crime.

Every horse has a passport and is micro-chipped as part of a traceability system. However, gardaí believe fraudsters have been manipulating the system for profit and Thursday’s searches aimed to assess the extent of the fraud.

Just over 12 months ago a batch of microchips was seized en route to Ireland from China. They were from Eastern European horses that had died years earlier.

Gardaí and the Department of Agriculture believe the chips were about to be presented to abattoirs in an attempt to pass off some horses as being fit to enter the food chain which were not.

Horses receiving certain medicines during their lifetime, for example, would not be fit for use as food, but a new chip could allow such a horse to bypass the rules and be accepted.

More than two dozen chips were found entering the State last March, alerting the authorities to the suspected abuses of the system now under investigation.

Horse owners are required to pay a fee to destroy an animal deemed unfit for human consumption. If one of these horses could be smuggled into the food chain, the owner of the animal could avoid that fee and would instead be paid for the horse.

The net difference between the fee they would be required to pay for destroying an animal and the fee they would receive for the horse would be more than €1,000 per horse, sources said.

Veterinary officials have found what they believe is clear evidence of the manipulation of the horse traceability system. People and commercial operations suspected of being linked to that fraud have been under covert investigation by gardaí and other agencies for some time.

Informed sources said arrests were not expected during the operation as the current phase of the inquiry was aimed at gathering evidence such as paperwork, electronic records and details of communication between suspects in the case.

“The Garda National Bureau of Criminal Investigation assisted by officials from the Department of Agriculture, Food and the Marine and the Food Safety Authority of Ireland are conducting planned searches at locations in Roscommon, Leitrim, Sligo, Westmeath and Kilkenny,” the Garda said in a statement.

“A total of seven sites are being searched including farms, houses and a commercial premises.”