Police said a Shepparton man, 18, was currently in police custody at the Shepparton police station.

It comes after a Cobram man, 27, handed himself into the Broadmeadows police station at 10am.

1.07PM: A teenager who was getting change to use a car wash said he witnessed the stabbing death of a young man outside a Cobram service station.

Reid Wilson, 18, said he was at the door of the Caltex service station on the corner of Station Street and the Murray Valley Highway when a fight broke out between two groups of young men about 10.30pm last night at the petrol bowsers. 

"They started grabbing each other's shirts and as they were doing that, one of them just pulled out a knife," Mr Wilson said.

Mr Wilson said he saw one of the men get stabbed in his stomach.

"It was crazy and everyone was yelling," he said

12.07PM: A man is in custody in relation to the stabbing death of a Cobram man last night.

Police said a Cobram man, 27, handed himself in to the Broadmeadows Police Station shortly before 10am.

He will now be interviewed in relation to the matter.

9.06AM: A number of people called Triple 0 in the moments after a young man was stabbed in Cobram, with paramedics unable to revive the 20-year-old.

Ambulance Victoria spokesman John Mullen said paramedics were called to the Caltex service station on the Murray Valley Highway and Station Street intersection at 10.30pm by several people.

It's not clear if they were witnesses or neighbouring residents.

An ambulance helicopter was on standby to transport the young man to hospital, but paramedics were unable to revive him and he died at the scene.

It's understood police spoke to a number of people at the scene. 

8.41AM: A man, 20, was stabbed to death in Cobram last night, his body found at a service station.

Police have confirmed there was a fight outside the Caltex service station on the Murray Valley Highway.

They were called to the scene at 10.30pm and the man is believed to have died soon after. 

Police said a number of men had left the service station in a silver Commodore. 

Homicide Squad detectives are investigating.

Anyone with information about the incident is urged to call Crime Stoppers on 1800 333 000.