The head of the French company at the centre of an international baby milk scandal denied Friday that it was responsible for the contamination that triggered a recall of formula in over 80 countries, calling it “an accident”.

Lactalis, one of the world’s biggest dairy groups, was forced to recall 12 million packages of powdered baby milk in 83 countries in December and January after being linked to an outbreak of salmonella poisoning in children.

French officials began investigating the company after at least 36 infants fell sick from drinking milk sold under the Picot or Milumel brands. Cases of suspected contamination were also reported among children in Spain and Greece.

The outbreak was traced to a Lactalis factory in Craon, western France.

CEO Emmanuel Besnier told a French parliamentary inquiry that a renovation of the plant in early 2017 “released salmonella which was inside the buildings”.

“It was an accident. Nobody inside the factory was responsible,” he told lawmakers.

Lactalis has come in for heavy criticism after it emerged that the company’s own tests found salmonella on a production line but that it did not report the finding because the bacteria was not found in the milk itself.

The company is facing several lawsuits over the outbreak.