THIEVES stole a $75,000 earthmover last week from a Berwick school under construction.
Narre Warren police said the incident at Beaconhills College in Kangan Drive occurred between 3.30pm on Monday, 1 May and 6.30am on 2 May.
Thieves broke into a shipping container that housed various tools.
Police believe a welder might have been used to burn through locks.
Police said a trailer or truck would have been needed to remove the excavator, valued at $75,000, and a large gas bottle, worth $10,000. Tyre marks were left at the scene.
Police have urged anyone with information to contact Narre Warren police on 9705 3111 or Crime Stoppers on 1800 333 000.