A portable nuclear device containing radioactive material that could be a danger to public safety has gone missing in the US state of Pennsylvania.

Authorities are currently searching for the device, which belongs to local construction inspection company KAKS and Company LLC.

The state’s Department of Environmental Protection (DEP) said the device, a portable nuclear gauge, is often used at construction sites to “evaluate the properties of building and road-bed materials”.

However, people could be exposed to radiation contamination if it is damaged or mishandled, the agency warned.

It said that the nuclear density gauge was safely stored inside a vehicle reported stolen in the city of Philadelphia.

When the vehicle was found, the gauge was missing.

The agency said there is “potential for damage to the radioactive source and spread of contamination” if the device’s sealed sources of radioactive material are badly damaged or struck by a vehicle.

David Allard, director of the Bureau of Radiation Protection, said in a statement: “It is critical for anyone who has information about the lost nuclear gauge to contact local authorities or DEP.

“As long as the device is not tampered with or damaged, it presents no hazard to public safety.”

Sky News affiliate NBC News reported that environmental authorities believe the gauge may have been damaged after the theft of the vehicle, which is why officials are urging anyone who encounters the device to not handle it and contact the authorities to allow a trained individual to recover it.

Exposure to low levels of radiation may not result in an immediate health risk but can cause a small increase in the risk of cancer over a lifetime, according to the US Environmental Protection Agency.

High levels of radiation exposure over a short period of time can cause nausea and vomiting.