Detective Inspector Dead Thomas said police had been on patrol along the Princes Highway in Dandenong when they saw the man collapse outside the BP on Potter Street at about 4.50 am.

The officers provided first aid until paramedics arrived.

However, the 39-year-old died at the scene.

Thomas said it appeared the man had been injured inside a nearby unit before fleeing to the street.

He said the attack may have taken place at about 4.35am.

No weapon has been found but police have located a phone outside, which will be examined in connection with the case.

Nobody has been arrested.

Thomas said at this stage, there was no suggestion the attacker lived at the address.