Police reportedly heard a gunshot from a residence in Calvert St about 7am today. A Victoria Police spokeswoman said the man died from "self-inflicted injuries".

The siege began about 11pm yesterday.

Police were called to the man's home where he was holding four people including two teenagers at gunpoint.

The Special Operations Group was called to the scene and successfully negotiated the safe release of all the hostages by 4:30am.

Despite ongoing negotiations, the man took his own life, a Victoria Police spokeswoman said.

A report will be prepared for the coroner.