Homicide Squad detectives are investigating the circumstances surrounding the death of a man in Port Melbourne this morning.
Emergency services were called to Rouse Street after a man was located with injuries in an alleyway about 9.55am.
The man, who is yet to be formally identified, was pronounced deceased at the scene.
A 36-year-old Port Melbourne man was arrested in a nearby carpark this afternoon.
He was taken to hospital under police guard.
During the arrest, a police officer sustained non-life-threatening injuries.
Police are making enquiries to determine the circumstances surrounding the incident and investigations remain ongoing.
Anyone who witnessed the incident, with dashcam/CCTV footage or information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au