Dozens of Sydney bakery diners sick

Dozens of diners are recovering after being struck by a suspected food poisoning outbreak that forced health authorities to shut down a Sydney bakery.

At least 40 people presented themselves to St George and Sutherland hospitals over the weekend after they consumed food believed to be prepared at the Box Village Bakery in Sylvania.

Thirteen of those people, including young children, were admitted for further treatment.

Initial tests showed the patients had suffered salmonella poisoning, a NSW Health spokeswoman said on Tuesday.

It's believed several patients had reported eating either chicken or pork rolls from the same southern Sydney bakery.

Up to 100 people are suspected to have fallen ill after eating food from the bakery at the weekend, with some suffering severe diarrhoea and vomiting.

The NSW Food Authority closed the bakery on Monday after a prohibition order was issued.

The shop will remain closed until an investigation into the incident is complete, a spokeswoman said.