The chips could well be down if a potato virus takes hold.

Potato mop-top virus, or PMTV, has been found on two properties in Canterbury.

Biosecurity New Zealand says if its found to be widespread, it could cause some productivity issues for growers.

Potatoes New Zealand chief executive, Chris Claridge, says the affected potatoes are from the Innovator variety, which are only used for potato chips.

"The industry is working closely with Biosecurity New Zealand to learn more about the virus, the impact it could have on growers, and to stop any risk of spread."

Affected potatoes can display symptoms including distortions to the skin, deep cracking, and rust-coloured arcs, streaks or flecks in the tuber flesh.