Victoria Police say they are concerned about the psychological state of a violent sex offender who is on the run.

A warrant has been issued for the arrest of Antonio Loguancio, 40, who police say has breached a supervision order.

He is also wanted for questioning about an assault on his partner in West Heidelberg last weekend.

Assistant Commissioner, Stephen Fontana, says police have been talking to Loguancio on the phone.

"We've been in communication with Antonio at different stages throughout the night," he told ABC local radio.

"He is quite agitated and we're making a plea to him to actually just to calm down and to contact us and surrender.

"He's quite concerned about the media reporting and it has upset him quite a bit."