A man has died from a stab wound to his chest following an argument at a home in Sydney’s inner-west on Sunday.

Three men were at the Spring Street address in Concord when emergency services were called following reports of a concern for welfare about 12:10pm.

When police arrived they found a man in his late 30s with a stab wound. He was given CPR but died at the scene and is yet to be formally identified.

He did not live at the property, according to police.

a police officer at a crime scne in concord after a man was fatally stabbed

Three men were at the house when emergency services arrived. (ABC News)

A second man, aged 41, was arrested, with charges “anticipated later this evening”. 

A 47-year-old man is assisting police and is not in custody. Both men lived at the residence and are in a relationship, police said.

Superintendent Christine McDonald described the alleged stabbing as “tragic” and the level of violence as “completely unnecessary”.

She also said the three men were from Sydney and all were friends, and that the victim and the man in custody had known each other for about eight years.

“You go to someone’s house on a Sunday afternoon for whatever reason and this occurs,” she said.

“It’s not something that I’m sure the victim was expecting would happen. And now multiple lives have been ruined by this incident.”

Cause of the argument under investigation

Police will allege the weapon used was a kitchen knife from the property which has been “seized”.

Superintendent Christine McDonald talks to the media about a fatal stabbing in concord

Christine McDonald described the incident as “tragic”. (ABC News)

Central to the investigation under Strike Force Matpalo is what caused the argument, however at this stage the incident is not being treated as domestic-violence related.

“We don’t know what the argument was about today, that will form part of the inquiries,” Superintendent McDonald said.

“And I know the detectives are currently working really hard to identify what the source of the argument was.”

In response to whether any of the men were known to police, Superintendent McDonald said “not adversely”.

“In relation to the 41-year-old man that we have in police custody right now, he has reported a matter as a victim before, and has minor traffic matters, but not adversely known to police,” she said.

“In relation to the victim, I can say that he also is not adversely known to police. 

“He has reported matters to police before, but not adversely known.”