Sydney: Nine Australians have contracted hepatitis A linked with eating contaminated berries from China, with the importer apologising Tuesday as the food scare spreads.

Manufacturer Patties Foods has recalled four products including the Nanna's and Creative Gourmet brands of mixed berries and Nanna's raspberries after infections in Victoria, Queensland and New South Wales.

They are all sold nationally in major supermarkets, having been packed in China.

The hepatitis A cases are linked with Nanna's Frozen Mixed Berries, with three other brands pulled off shelves as a precaution.

"Hepatitis A virus infection is uncommon and normally associated with travel to countries affected by endemic hepatitis A," said Rosemary Lester, chief health officer in Victoria state, where three cases have been reported.

"The only common link between the cases is consumption of this product -- there is no overseas travel or common restaurant exposure."

Poor hygiene among Chinese workers and potentially contaminated water supplies in China are likely to have caused the outbreak, experts said.

"In this situation, the most likely culprit is poor hygiene at the site of production," said Enzo Palombo, a food health and safety expert at Swinburne University of Technology.

"Hepatitis A is transmitted by the so-called 'faecal-oral' route -- an infected person sheds the virus in their faeces which then contaminates food or water.

"The virus either directly contaminates the food through a food handler not washing their hands properly or it could come from contaminated water used to wash the berries."

Hepatitis A is a viral disease that affects the liver, causing abdominal pain, nausea, vomiting, fatigue and jaundice. It has an incubation period of up to 50 days. "As a company, we apologise to our consumers and customers for the concern and distress this is causing," said Patties Foods chief executive Steven Chaur.