The Pepino Mosaic Virus has been identified for the first time in New Zealand in indoor-grown tomato crops.
New Zealand growers could lose some of their international markets because of it.
Tomato NZ's Helen Barnes says it is not known how the virus made it to New Zealand but it could have come in on equipment or in seeds.
She says fruit from infected plants can be safely eaten.
Growers need to introduce strict hygiene measures, keep a close eye on their crops and contact Biosecurity New Zealand for advice if they suspect their plants are affected.
New Zealand exports tomatoes to 18 countries including Australia, Japan and the Pacific Islands.
Australia does not have the Pepino Mosaic Virus.