More than 3,000 tonnes of Kinder products have been withdrawn from the market over salmonella fears leaving a dent of tens of millions of euros, a company official told France's Le Parisien daily Thursday.

Nicolas Neykov, the head of Ferrero France, said the contamination came "from a filter located in a vat for dairy butter", at a factory in Arlon in Belgium. He said the contamination could have been caused by humans or raw materials.

Chocolate products made at the factory in Arlon, southeastern Belgium, were found to contain salmonella, resulting in 150 cases in nine European countries.

Eighty-one of these were in France, mainly affecting children under 10 years old.

The head of Ferrero France said the contamination that caused more than 3,000 tonnes of Kinder products to be withdrawn came "from a filter located in a vat for dairy butter", at a factory in Arlon in Belgium The head of Ferrero France said the contamination that caused more than 3,000 tonnes of Kinder products to be withdrawn came "from a filter located in a vat for dairy butter", at a factory in Arlon in Belgium Photo: BELGA via AFP / ERIC LALMAND

The factory's closure and the health concerns were blows to its owner, Italian confectionery giant Ferrero, coming at the height of the Easter holiday season when its Kinder chocolates are sought-after supermarket buys.

"This crisis is heartbreaking. It's the biggest removal of products in the last 20 years," Neykov said.

But the company hoped to be able to start up the factory again, with 50 percent of health and safety inspections to be carried out by an approved "external laboratory" in the future, instead of the previous system of only internal reviews.

"We have asked for a reopening from June 13 to relaunch production as soon as possible," he added.