Paris prosecutors with expertise in public health have launched an investigation into a salmonella outbreak associated with an international recall of baby milk sold by Lactalis, one of the world’s largest dairies based in western France.

The baby milk recall is the largest since the melamine scandal rocked China a decade ago. Prosecutors are investigating what happened around concerns involving fraud, negligence and endangering the lives of others.

Public health officials say, 31 French infants have suffered from Salmonella infections in recent months after consuming baby milk produced by the Lactalis plant in Craon, located in Western France. All the infants recovered, but 16 did require hospital care.

The French dairy found Salmonella in the Craon plant after renovations earlier this year. It apologized to customers and recalled products in about 30 countries. The latest expanded recall includes products produced as far back as February 2016. The large-scale recall started on Dec. 10 when Lactalis recalled 7,000 tons of baby milk packets with Salmonella contamination.

Lactalis was one of the companies that moved aggressively into the Chinese baby milk market after China’s local dairies in 2008 were found using melamine, an industrial chemical, as a bulking agent in milk and infant formulas.

At least 300,000 Chinese infants were sickened, and six died as a result of the melamine scandal. Melamine caused kidney stones and other renal damage to infants.

Lactalis is one of the world’s largest dairy companies. It gained market share in China from parents more concerned about food safety than higher prices.

The family-owned company is the largest dairy group in the world with 230 industrial plants in 43 countries employing 75,000. In Europe, it is the largest in dairy and cheese, milk collection and cheese production.  In addition to Europe, its products are sold in Asia, Africa, and the Middle East.  It owns numerous French and international brands.  It has done business under the name of Lactalis since 1999.