A 22-year-old man has been charged in connection with a shooting earlier this year in Western Sydney that killed the brother of bikie kingpin Tarek Zahed.

The Comanchero boss survived the assassination attempt, but was left fighting for his life and spent months in hospital after the Bodyfit Fitness Centre at Auburn was hit with a spray of bullets just after 8pm on May 10.

His brother, Omar, received shots to the arms, stomach and legs. The 39-year-old went into cardiac arrest and died in the gym foyer in what authorities described as a "horrific and confronting" scene.

Forty-one-year-old Tarek was shot up to 10 times, including the head.

Prior to the shooting he had been living in Victoria and was visiting NSW despite warnings by police that he was a marked man.

Detectives arrested Adam Ganaim at Sydney domestic terminal on Saturday at about 10:30pm as part of their ongoing investigations.

He was taken to Mascot police station where he was charged with concealing a serious indictable offence.

Ganaim was refused bail and is due to appear at Parramatta Bail Court on Sunday.

At the time of the shooting, squads fighting the spiralling gang violence across Sydney were boosted in what NSW Police Commissioner Karen Webb said was the need "to keep tackling this".

State Crime Command's Homicide Squad under Strike Force Leary were initially tasked with the investigation, which then formed part of Task Force Erebus —an operation coordinating the efforts of gang-fighting squads.

In August this year, Tarek Zahed was charged over an alleged 2014 murder.

His arrest followed a years-long investigation into the 2014 death of Youssef Assoum at Bankstown.