Saputo, a Canadian-based dairy company, has expanded its product recall of certain Neilson partly skimmed chocolate milk products, as they may have been contaminated with Listeria monocytogenes.

The company issued a public warning as well as closing the production line where the recalled Neilson branded partly skimmed chocolate milk product was manufactured.

Initially, Saputo recalled four-litre bags of Neilson-brand partly skimmed chocolate milk, but now the recall has been expanded to include other pack sizes, reported foodsafetynews.com.

"The products were manufactured at its Georgetown, Ontario facility, and carry best before dates of up to 22 June."

Though the exact cause of the incident is yet to be ascertained, Saputo voluntarily recalled the products as a precautionary measure. The recall list includes products manufactured until 3 June 2016.

The products were manufactured at its Georgetown, Ontario facility, and carry best before dates of up to 22 June. No other Neilson chocolate milk products are affected by this recall.

The company also stated that it will closely work with the Canadian Food Inspection Agency in the investigation.

There have been reported illnesses that may have been caused due to consumption of these dairy products. Lab tests are underway to confirm any possible link.

The affected products have been sold or distributed via retail stores, supermarkets, restaurants, and hospitals in Ontario and Québec.

Food or beverages contaminated with Listeria monocytogenes bacteria may not appear or smell spoiled but can make people sick. Symptoms can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness.