Irish dairy exporter Ornua is facing a lawsuit in the US state of California for alleged “misleading” claims about its Kerrygold butter brand.

The case is being brought before the United States District Court for the Southern District of California relating to claims that the brand is “false advertising”.

The plaintiff, an individual named Dyami Myers-Taylor, is attempting to sue Ornua North America and Ornua Co-operative.

Myers-Taylor apparently took up the lawsuit on behalf of himself and “all similarly-situated persons who were misled into purchasing Kerrygold products due to false and misleading advertising”, the official class action complaint details.

The alleged claims against Ornua entail: violations of the California Consumer Legal Remedies Act, the California False Advertising Law, the California Unfair Competition Law; breach of express warranty; breach of the implied warranty of merchantability; and for fraud and negligent misrepresentation.

According to the Irish Times, Myers-Taylor is a San Diego-based real-estate executive, who argues that Irish cows are not exclusively grass-fed because they often eat other materials, such as grain or soya, when weather is bad and there is no grass to eat.

He also alleges some of the concentrates fed can be genetically modified.

Myers-Taylor claims he would never have bought Kerrygold had he known Irish cows are not exclusively grass-fed, the publication adds.

A spokesperson for Ornua rejected the claims, saying: “We believe our products are marketed in accordance with applicable laws and regulations and will vigorously defend claims which propose otherwise.”

Ornua also assured that Kerrygold dairy products do not contain Genetically Modified Organisms or ingredients.

The diet of Irish cows is primarily grass-based; however they do consume a small portion of supplementary feed for health and well-being and this supplementary feed is comprised of locally-grown crops like wheat and barley.

As a small island, with a temperate climate, Ireland does not have enough suitable land and climatic conditions to grow some crops locally; therefore, a small number are imported.

Given the predominance of GM planted crops globally, some of this imported feed may be from GM sources.

These imported crops fully comply with strict European and Irish legislative requirements on labelling and traceability, the exporter affirmed.