New Zealand flatworms have added at least £100,000 to the cost of putting up a new primary school on the Black Isle.
Land surveyors discovered tonnes of earth removed for the foundations of Cromarty Primary are infested with the environmental menace. However, environmental rules mean the soil cannot be reused for gardening or building properties, but must be disposed at landfill sites, incurring huge costs.
The total bill for removing the flatworms has yet to be finalised, but the project's cost has leapt by £750,000 to £2.75 million and the matter will today be reported to Highland Council's adult and children's services committee.
Councillor David Alston said: "There is a problem in Cromarty with New Zealand flatworm. I know, I have them in my own garden. But it was a very unwelcome discovery at the site of the proposed new school building.
"Normally somebody would want good quality top soil, but not if it's contaminated with flatworm."