The horse meat investigation that led gardaí to search seven premises in five counties this morning had its origins in the seizure of a batch of microchips by customs officers more than 18 months ago.

The microchips which had arrived in Ireland from China contained codes.

A subsequent investigation was able to match those codes to horse passport numbers for animals that had been slaughtered in eastern Europe and elsewhere up to ten years previously.

This led the Special Investigation Unit of the Department of Agriculture to begin a trawl through international records to try to trace the animals involved more than a year ago.

It is understood that the evidence the unit amassed included at least 2,000 bogus horse passport documents that were used to sell horses for human consumption. All of the horse meat involved was for export to the European marketplace.

Horses that are not officially certified for human consumption have little or no value in the food industry. However, those with the necessary documentation, along with a matching microchip, could be could be worth in excess of €600 per animal depending on their carcass weight.

Gardaí and Department of Agriculture investigators suspect an organised gang, or an organised operation of some sort, was implanting microchips into worthless animals and then presenting those animals for slaughter with fake animal passport documentation. This way animals unfit for human consumption could have entered the human food chain.

While gardaí do not believe any of the horse meat was sold into the Irish market, there would be serious concerns about the health implications of the sale of illicit horse meat into countries elsewhere in Europe including Belgium, France, and the Netherlands.

For instance horses treated for inflammation and lameness are usually injected with a drug called Phenylbutazone commonly referred to as Bute.

This drug, however, can cause severe adverse effects in humans including the suppression of white blood cell production. In addition horses could be injected with hormones or simply be ill or too old for consumption.

Before any horse can be certified for human consumption a veterinary surgeon has to certify that its meat does not contain any residues of Bute and or other drugs harmful to humans, and that it is fit for human consumption. This kind of information and certification is contained in the horse passport documentation now suspected to have been falsified.

The seven garda searches took place in counties Roscommon, Leitrim, Sligo, Westmeath and Kilkenny.

The seriousness of the investigation is clear from the extent of the garda involvement with the National Bureau of Criminal Investigation, the Criminal Assets Bureau, the Garda National Drugs and Organised Crime Bureau, and the Garda National Cyber Crime Bureau all involved along with investigators from the Food Safety Authority of Ireland (FSAI) and the Department of Agriculture.

Detectives are trying to determine if individuals have been complicit in fraudulent activities or if they may have been duped.

Two years ago an investigation co-ordinated by Europol dismantled an organised crime group trading in horsemeat unfit for human consumption using forged animal identification and fake microchips. 

The investigation, which was carried out in co-ordination with authorities in Spain, Belgium, France, Italy, Portugal, Romania Switzerland and the UK, led to the arrests of 65 people in Spain.

They faced charges including animal abuse, forgery, crimes against public health, and money laundering. Bank accounts were blocked, while properties and luxury cars were also seized as a result of that operation.

Gardaí said today that the searches in Ireland are part of an ongoing investigation but that as this is a search and evidence gathering phase in an ongoing investigation they will not be commenting further at this time.

A refusal to comment citing the exact same reason was given by the Department of Agriculture and by the FSAI.