Police return to the scene of Brothers 4 Life sibling's murder

Police have returned to the scene of a shooting murder in Sydney's southwest as they try to piece together what happened to the brother of a notorious gang founder.

Members of the NSW Criminal Groups Squad have been monitoring the movements of the Hamzy and Alameddine families after Mejid Hamzy, 44, was found gunned down outside his Condell Park home on the morning of Monday, October 19.

Mejid Hamzy is the brother of Brothers 4 Life founder Bassam Hamzy.

Today detectives returned to the Simmat Avenue address and surrounding properties to gather more information on what led to Mejid's death.

Last month it was revealed police banned 22 people linked to the two families from travelling to certain parts of Sydney under 72-hour public safety orders to try and prevent tensions from escalating.

As fears linger of a gangland war brewing on Sydney streets, police are in the process of seeking serious crime prevention orders in the Supreme Court.

"Attention from police will not stop, we are having people dying in the street, we are sick of it," Detective Superintendent Robert Critchlow said.

"We are going to use every weapon available to us in the legislation ... to stop this behaviour."

Bassam Hamzy is currently jailed in Goulburn's supermax prison.

Less than a week after his brother's murder, his cousin Mohammed Hamzy, known as Little Crazy, was stabbed in prison.

According to police, homes belonging to both Hamzy and Alameddine families have been targeted and last month officers were called in to break up a street brawl allegedly involving members of the two groups.

Police are not suggesting any members of the Hamzy or Alameddine families were involved in the killing of Mejid Hamzy, or the drive-by shootings at any of the family homes.