Police say a potentially dangerous nuclear gauge has gone missing in the Toronto area.

They say the gauge, which contains sealed radioactive material and is used to measure soil thickness and moisture content, was lost between 6 a.m. and 7 a.m. on Wednesday.

Police say it was last seen in a pickup truck in west-end Toronto.

They say it was noticed missing after the truck made numerous stops in Toronto and Brampton.

Toronto police say the gauge could be "harmful with prolonged exposure."