A fifth person has contracted Hepatitis A after eating a mixed berry product, Ministry of Primary Industries confirmed.
"All five people who have fallen sick with Hepatitis A have the same strain, and all five have consumed the Fruzio Mixed Berry product recalled this month," Ministry of Primary Industries (MPI) plants food and environment director Peter Thomson said.
He said the investigation was ongoing and they weren't ruling out the possibility of further recalls.
Mr Thomson advised people to wash their hands before eating and preparing food.
Anyone who was concerned should briefly boil any frozen berries before eating them, or ensure cooking exceeds 85C for one minute.