A man has been charged with murder after allegedly stabbing a friend to death in an argument at his Sydney home.

Emergency services called to a house on Spring Street in Concord just after midday yesterday found a 37-year-old man with stab wounds to his chest.

He was treated by paramedics but pronounced dead at the scene.

A 41-year-old man was arrested at the home and taken to Burwood police station where he was charged overnight with murder.

He and a 47-year-old man, with whom he was believed to be in a relationship, lived at the house.

Police say the victim and his alleged killer had known each other for eight years.

The nature of their relationship is now part of the investigation

The 47-year-old man was also speaking to police but had not been arrested and police were not expecting to lay charges.

Superintendent Christine McDonald said it was a "terrible incident".

"This level of violence is completely unnecessary," she alleged.

"This is a terrible incident, you go to someone's house on a Sunday afternoon for whatever reason, and this occurs.

"It's not something I'm sure the victim was expecting would happen, and now multiple lives have been ruined by this incident."

She said there was an argument before the alleged stabbing.

No one at the house at the time was known to police.

A crime scene has been set up and investigations are continuing.

The 41-year-old was refused bail and expected to appear at Burwood Local Court today.

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