A bakery in Sydney’s south has been closed down pending an investigation after up to 40 people fell ill with food poisoning over the past week, with 13 admitted to hospital for treatment.

The Box Village Bakery in Sylvania has been closed as the Food Authority investigates whether it could be the source of the outbreak.

There are reports that those who fell ill may have eaten chicken rolls or chicken schnitzel rolls from the bakery.

Dr Mark Ferson, public health director for south-east Sydney, told 2UE radio that as of yesterday there had been 40 people who attended Sutherland and St George hospitals with symptoms of food poisoning.

He said salmonella had been found in some of the patients.

“We think about 13 of those have been admitted to hospital. People started becoming sick on Friday and the hospital informed us on Sunday that they were getting a number of patients in.”