Police say anyone who tampers with radioactive equipment that was in the back of a ute stolen in Christchurch could end up with serious injuries.
They say a white Ford Courier ute reported stolen from a private company in the suburb of New Brighton on Tuesday was carrying a tool called a nuclear density meter.
The meter measures soil density and moisture content, and contains two small radioactive sources inside a stainless steel casing.
Police say the amount of radioactive material is relatively small and is inside a stainless steel casing, but removing it would be dangerous to people's health.
They say the vehicle is clearly labelled with signs saying Class 7 Radioactive.
Inspector Marc Paynter, from Police National Headquarters, says no one should try to use the equipment or remove the material.
He says whoever took the meter should let police know where it is, rather than tamper with it or dump it.
"We don't want it dumped, we don't want it hidden, we just want to locate it and make sure it's looked after safely and in a way where there's no public risk.
"The last thing we want is for someone to start tampering and pulling this thing apart."
Inspector Paynter says trying to use the equipment, or remove the dangerous material, could result in injuries, similar to burns, deep in the body.