Birthday party stabbing leaves two relatives dead after 20-person brawl

Police were called to Clyde North, in Melbourne's outer southeast suburbs, at 9.30 pm on January 16 after receiving reports of a fight that turned into a 20-person brawl on Observatory Street.

A 23-year-old man and a 54-year-old man, who were "closely related", were found suffering wounds that were "consistent with a stabbing".

The victims were treated for their injuries but both died at the scene.

Superintendent Janet Stevenson said the family was reeling after learning of the tragic deaths.

"It should have been a great celebration," she said.

Investigators are interviewing the other people present at the party during the alleged fight.

Police wish to speak with "several" people who left the party before officers arrived and a crime scene has been established at the home.

Superintendent Janet Stevenson urged the attacker or attackers to report to a police station.

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