Northern Grampians highway patrol officers are seeking information after receiving reports of damage to roadwork bollards near Murtoa.
Horsham Police's Mark Davies said officers received a report about the damage on the Wimmera Highway on Saturday morning.
He said police believed the damage had been done by a vehicle, and that anyone with information should call highway patrol on 5355 1500.
Northern Grampians Highway Patrol Acting Sergeant Jason Brown said the damage took place on Friday night, and "at least 60" bollards were damaged.
In March, Regional Roads Victoria announced nearly three kilometres of the highway was set to undergo $2.9 million worth of roadworks in the following months.