Diesel was stolen from a building site on the outskirts of Kilkenny city.
Three men, all wearing hoods, were seen on CCTV entering and leaving the site on the Old Golf Links Road at around 9.30pm on Monday night.
Gardaí are appealing to anyone who was in the area who saw any suspicious activity to come forward.
They are particularly appealing to anyone who may have dash cam footage to contact the station in Kilkenny.