A 34-year-old man has been arrested and taken to Mascot Police Station after a body was found in Chifley.
A 47-year-old man was found dead inside his unit at approximately 6.30pm on Wednesday night.
It is the same apartment building where a fire occurred earlier in the week, but it is understood that there is no link between the man's death and the fire.
The death is being treated as suspicious and police have said that the victims sustained a "number on injuries".
The cause of death will be determined by a post-mortem.
The 37-year-old man is currently being questioned by police and no charges have been laid.