Homicide Squad detectives are investigating the circumstances surrounding the death of a man in Thomastown on Sunday evening.

Emergency services responded to reports a man was shot outside a Victoria Drive address shortly after 7.30pm.

Despite efforts to revive the man, who is yet to be formally identified, he was declared deceased at the scene.

No arrests have been made at this stage.

Anyone who witnessed the incident, with CCTV/dashcam footage or information is urged to contact Crime Stoppers on 1800 333 000 or online at www.crimestoppersvic.com.au