Man shot dead in Sydney's southwest

Paramedics treated the man, believed to be in his 20s, but he died at the scene. He is yet to be formally identified.

The street remains closed to traffic while detectives investigate. It has not been confirmed if the shooting is gang related.

However, The Sydney Morning Herald reported on Saturday the deceased is the nephew of gangland figure Mahmoud "Brownie" Ahmad, who was publicly executed in Greenacre in late April.

Saturday's incident is the third fatal shooting in recent weeks, including Mr Ahmad's death, and comes only days after two Comanchero bikies were gunned down at a western Sydney gym.

Omar Zahed, 39, was killed and his brother, Comanchero bikie boss Tarek Zahed, 41, was critically wounded at the Body Fit gym in Auburn on Tuesday night.

NSW Police established a new strike force to investigate the shootings.