A Malmsbury Youth Justice Centre worker suffered serious upper body injuries in an assault by an inmate on Monday night.
The male victim was taken to hospital in a serious but stable condition.
A Department of Justice and Community Safety spokesperson confirmed the incident occurred about 7pm.
“A staff member was transported by Ambulance Victoria to hospital for treatment and Victoria Police were notified,” the spokesperson said.
“Violence toward staff is absolutely unacceptable and safety is of utmost importance in youth justice centres.
“Victoria takes a zero-tolerance approach to violence and assaults in youth justice centres.
“All incidents and allegations are referred to Victoria Police.”