Telecommunications, transport and electricity companies are on alert after a series of copper cable thefts in Central Victoria.
Copper is commonly used in electrical motors, wiring, and anything that requires electricity.
It has a wide range of uses including powering homes, in mobile network technology, and streetlights.
The price of copper is $12.30/kg.
Last year it reached a record-high market price of $14/kg.
On Sunday morning, Telstra technicians discovered the Mount Holden base station in Sunbury was running on backup batteries, due to copper theft.
An investigation found power cables for both Telstra and NBN had been cut and removed, disrupting the mobile coverage for Woodend, Mt Macedon, and surrounding areas.
Police are investigating the copper thefts in Sunbury.
They say cables were cut from two phone towers on May 13 and May 16 in Mt Holden Reserve.
"It's understood between $5,000 to $10,000 worth of copper was stolen, causing damage of up to $400,000 to the business," a Victoria Police spokesperson said.
Copper thieves cash in the cables at scrap metal yards or online.
Community at risk of electrocution
Powercor has also been a victim of the rise in copper theft in regional Victoria.
"We've had incidents where offenders have ripped out underground copper cables from street lighting and other electricity infrastructure, leaving the community without lighting or power," said Powercor's manager of protective security and network facilities, Michael Hayes.
Thieves put themselves and the community at risk of electrocution and death, by leaving wires exposed.
"In some cases, we've had live wires left exposed in busy public areas. These criminal acts pose a danger to our customers, communities and staff," Mr Hayes said.
He said Powercor had experienced recent incidents across Central Victoria, including in Woodend, Gisborne, and along the Calder Highway.
It is investing in smart technology and surveillance systems to catch criminals in real-time.
"Powercor works closely with Victoria Police and other agencies to identify and target copper theft hotspots," Mr Hayes said.
"If you see copper being stolen, call triple-0.
"You can report exposed wires to us on 13 24 12. Anyone wishing to report anonymously those they suspect may be involved in copper theft can report it to Crime Stoppers on 1800 333 000."