Anyone with information about stolen radioactive material in Dublin is being urged to contact the Radiological Protection Institute of Ireland as soon as possible.
Seven lightening preventers were taken during a burglary in Swords over the weekend.
Gardaí have warned they are extremely dangerous.
The preventers were used to prevent damage to buildings during the 50s in Ireland - and Professor in Experimental Physics and Trinity College Dublin, Ian McCauley says there may be more that the RPII don't know about:
The stolen items look like this and are about the size of a cereal bowl
Gardaí are warning that this material is highly dangerous and should not be touched or approached.
Anyone who discovers these items should contact the gardaí at Swords on 01-6664700 or the Radiological Protection Institute of Ireland on 01-2066913 immediately.