A nuclear gauge containing radioactive sources was one of a number of items stolen during a theft that took place overnight.
Officers were alerted to the theft of a number of items from a van parked in The Downs, Highlands, Drogheda Co. Louth.
A Troxler Nuclear Moisture Density Gauge, containing a radioactive source was among the items taken during the theft.
The theft occurred at some point between 6pm on Monday evening and 6.30am on Tuesday morning.
A Garda Siochána spokesperson said: "An Garda Síochána have been informed by the EPA (Environmental Protection Agency) that members of the public should be aware that there is a potential risk of exposure to radiation if an individual comes into contact with this item. In particular, if the case is opened and the equipment is activated.
"Gardaí are appealing to anyone who may have information in relation to this incident and any person who may have witnessed any unusual activity in the Highlands area between 6pm yesterday and 6:30am this morning, to come forward to them.
"Any person with information in relation to the theft or whereabouts of this item is asked to contact Drogheda Garda Station on 041 987 4200, the Garda Confidential Line on 1800 666 111 or any Garda station."
