Canadian Food Inspection Agency officials say potato wart has been found in five fields on P.E.I. since the beginning of an investigation in August.
Back in August, the agency confirmed the presence of potato wart in a single, 14.1-hectare field on a farm.
The investigation continued after that.
There are now a total of five cases.
But four of the affected fields are located on the same property, and the fifth case is closely linked through the movement of potatoes.
Agency officials said it's important to note that the additional finds were not unexpected due to their link or proximity to the initial find.
The CFIA said it is actively administering the Potato Wart Management Plan, which includes soil sample collection and testing as well as post harvest field surveillance activities.
Officials said all results to date support the conclusion that these are isolated incidents and that potato wart is not a pest which is widespread on the island.
Potato wart poses no risk to human health or food safety. However, it can reduce yield and make affected potatoes unmarketable.