Lactalis CEO Emmanuel Besnier has warned the French dairy giant could have been producing infant formula tainted with salmonella for more than a decade.

The company has recalled more than 12m tins of formula from 80 countries after late last year children fell ill from drinking formula made at its plant in Craon, north-western France.

The affair has bruised the reputation of Lactalis and of the wider French food industry after a botched recall meant tainted products were still on sale weeks after the link between the formula and the cases of illness was made.

Privately-owned Lactalis is under intense scrutiny. In an interview with Les Echos on Wednesday (31 January), the second the normally publicity-shy Lactalis CEO, Emmanuel Besnier, has given to the French media since the scandal broke, he said the same strain of salmonella had been found at the Craon site in 2005 before it was owned by the business.

However, Besnier also told Les Echos Lactalis had found salmonella at the site between 2005 and 2017 “in the environment” at the facility. Under French law, companies only have to notify the authorities if products are tainted.

He added: “It can not be excluded that babies have consumed contaminated milk over this period.”

In the same interview, Besnier said Lactalis could now say the strain of salmonella that has caused this latest affair was introduced at the Craon plant during renovation work last February. He said Lactalis was permanently closing part of the facility in the wake of the latest contamination.

Besnier also told Les Echos the situation was “the biggest crisis I’ve ever had to face as a boss.”

He said Lactalis could not yet be precise on how much the affair will cost the business but estimated the bill “will be very high, several hundred million euros”.

Besnier added: “This case could cost us our export license for a still undetermined period.”