Government food safety specialists are investigating whether several popular brands of frozen berries in New Zealand are linked to 12 Hepatitis A cases.
Twelve people have contracted the virus and seven have been hospitalised.
Ministry for Primary Industries deputy general of New Zealand food safety Vincent Arbuckle said frozen Serbian berries were under investigation because of a possible link.
Arbuckle said eight of the 12 cases were linked by genetic sequencing, meaning they were likely exposed to the same source of the virus.
Foodstuffs has recalled various brands of Pam's frozen berry products and is in the process of removing them from shelves around the country.
These include Pams frozen mixed berries 500g, Pam's frozen two berry mix 750g and 1kg, Pam's frozen smoothie berry mix 500g and Pam's raspberries 350g and 500g.
Arbuckle advised people to check if they had any of the recalled products and not eat any of the raw frozen berries.
The situation was evolving, he said.