TORONTO — Canadians are being warned to stay away from certain Siena brand meat products amid an expanding investigation by health authorities.

The Canadian Food Inspection Agency and Siena Foods say samples of Siena brand Coppa and Siena brand Prosciuttini, with best before dates between June 20 and June 22, tested positive for Listeria monocytogenes.

The agency says it is aware of reported listeriosis illnesses in Ontario and is working with the province's health authorities to investigate the cases.

The Toronto Star says the listeria outbreak has sent two people in Ontario to hospital and has sparked an investigation into two deaths which occurred while the products were still on store shelves.

Ontario's chief medical officer Dr. Arlene King told the Star the Siena products are being targeted as a possible cause.

Siena has recalled all affected products which may have been distributed nationally.

The symptoms of listeriosis include a high fever, severe headache, neck stiffness and nausea. Pregnant women, the elderly and those with weakened immune systems are particularly at risk.