Police were called to a property on William Blofield Ave around 11.10pm to reports a person had been fatally stabbed during an altercation.
Another person was seriously injured.
Police are speaking to a number of witnesses and a person of interest, who is assisting with inquiries, a spokesperson said on Saturday morning.
The party was in a residential street, in a state housing subdivision between Wesley Intermediate School and the south-western motorway.
At the time, Inspector Kerry Watson confirmed the stabbings occurred at a gathering at a house there, late on Friday night.
“Just after 11 o’clock tonight we got numerous calls for assistance from a street in Mt Roskill,” Insp Watson said. “We were told there was a fight occurring.”
The first man was located with critical injuries, and ambulance staff were unable to revive him.
A witness said what appeared to be a body could be seen lying on the road in front of a police car.
Around the corner on Denny Ave, paramedics assisted a person with serious stab wounds. Inspector Watson said the person was taken to hospital in a serious condition.
Police communications staff confirmed criminal investigations detectives were investigating the incident in Mt Roskill. Watson described it as “a very large scene cordoned off”.
Officers at the scene had arrested and cuffed a man, a bystander said, though the arrest was not thought to be directly related to the stabbing.
Police said there were people helping with inquiries, but they appealed for help from any other members of the public who had information or had seen anything.
Detective Senior Sergeant Glenn Baldwin urged anyone with information that may assist Police to call 09 3026 557 or Crimestoppers anonymously on 0800 555 111.
Sunday Star Times