But Lehagre told French news agency Agence France-Presse on Sunday that his company had been "fooled" by a French supplier. "We were victims," he said, according to AFP.

Latvanen credits his company with uncovering "a serious case of fraud."

"What has happened with Comigel is a crime, a scandal," he said.

While Findus has begun legal action in Sweden, the British arm of Findus said it is considering legal action against suppliers as well.

Tests showed up to 100% horse meat

One food supplier in Britain, Aldi, said tests on random samples demonstrated that the withdrawn products contained between 30% and 100% horse meat.

Samples of the affected Findus lasagna contained between 60% and 100% horse meat, according to UK and Irish food safety inspectors.

In January, the Food Safety Authority of Ireland found that 10 out of 27 hamburger products it analyzed in a study contained horse DNA, while 23 of them -- or 85% -- tested positive for pig DNA.

Of the 10 burger samples, nine were found to have very low levels of horse DNA, the inspectors said. But in one sample from Tesco, Britain's largest retailer, the horse meat accounted for about 29% of the burger.

Tesco apologized and vowed to make sure it never happens again.

Irish officials blamed ingredients from Poland.

Concerns about a veterinary drug

While horse meat is not itself a food safety hazard, food inspectors are concerned it may contain the veterinary drug phenylbutazone, or "bute," commonly used to treat horses.

Meat from animals treated with phenylbutazone may pose a risk to human health and is not allowed to enter the food chain.

Tesco said it tested for the chemical in the tainted spaghetti bolognese products but found no trace.