The brother of a man bashed and stabbed to death in Melbourne on the weekend after he tried to break up a brawl says the assailants may have fled the country.
"I've had some information on one, possibly three of the offenders have fled the country to Thailand," Shane Mitchell told Fairfax Radio Network on Monday.
"By all accounts they could have been on a plane as early as lunchtime early yesterday."
Mr Mitchell said police had indicated they had a strong chance of extraditing at least one of the men.
Luke Mitchell was stabbed five times and kicked while he lay on the ground about 2.16am (AEST) on Sunday as his friends and sister-in-law Daniella, Shane's wife, pleaded with the attackers to stop.
He died later that morning in hospital.
Shane Mitchell said one of the men was quite seriously injured in the attack and police believe they could link the DNA of that person to the crime scene, with the hope of extraditing the man back to Australia.
Mr Mitchell said a car believed to belong to the attackers had been found dumped not far from the scene in Sydney Road, Brunswick.
Police had tracked the car to an address and staked out the home, but nobody had been found, Mr Mitchell said.
Mr Mitchell said his brother had stepped in to break up a brawl outside the Spot nightclub in Sydney Road, Brunswick, in the early hours of Sunday morning, that was threatening to spill over and involve his sister-in-law who was calling for a stop to the violence.
Luke Mitchell and his sister-in-law were then dropped off by friends at a 24-hour store to hail a cab but were confronted by the attackers who stabbed and kicked Luke.
Mr Mitchell said Victorian Premier John Brumby and Victorian Police Chief Commissioner Simon Overland needed to take the lead to clean up the streets.
"I really think that John Brumby, Simon Overland, whoever needs to get together ... with the police to be able to show some presence and show some powers on the street, because this is just getting out of control."
Mr Mitchell said his brother's death was the "tragic loss of a beautiful, beautiful person and completely unnecessary".
He said his brother was a "gentle, gentle person".