Bacchus Marsh police are investigating a series of copper wire thefts in Darley.
Unknown offenders have taken the wire from a traffic signal site in Darley on four occasions.
The thefts have taken place between Friday 31 January and Saturday 8 February.
The theft of the copper wiring results in the loss of power to traffic signals and street lighting.
The offending leaves live wires exposed at the site posing a risk to public safety.
The investigation is ongoing.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au