Two people are believed to be trapped underground after a mine collapsed on the outskirts of Ballarat.
Victoria Police said emergency services were responding to reports of a collapse at Ballarat Gold Mine in Mount Clear about 4.50pm on Wednesday.
A spokesperson said the situation was developing and further information would be provided when available.
Ambulance Victoria said paramedics were at the scene and an air ambulance has been dispatched.
The mine's website states it operates deep beneath buildings, streets and homes and has an extensive network of tunnels.
It is owned by Victory Minerals.
Worksafe inspectors and a technical specialist are responding.
Ballarat Gold Mine said declined to comment.
The Mount Clear area has been the focus of the search for Ballarat mother Samantha Murphy, however, there is no information to suggest any link.
Patrick Orren Stephenson has been charged with murdering the mother of three at Mount Clear and her body has not yet been found.