Yusuf Guney Nazlioglu on Monday was charged by detectives investigating Hawi's murder with possessing an unauthorised pistol, not keeping a firearm safely and acquiring a pistol while subject to a firearms prohibition order.

The 37-year-old and fellow Lone Wolf outlaw motorcycle gang member Ahmad Doudar, 38, are accused of murdering Hawi, who was shot multiple times as he sat in his luxury vehicle outside a Rockdale gym in February.

Detectives say they found a loaded .22 revolver in a basement car park at the Toaster apartment complex at Circular Quay on September 21.

Nazlioglu's matter was mentioned briefly in Parramatta Local Court on Monday. He did not apply for bail and it was formally refused. He is due back in court on Wednesday.

Police claim Nazlioglu and Doudar had a financial motive to kill Hawi, 37, who was jailed over the 2009 bashing death of Hells Angels associate Anthony Zervas in a wild brawl at Sydney Airport.

They were charged with murder in mid-August. A third man, 36-year-old Moustafa Salami, has been charged with being an accessory after the killing.

Hawi had mainly flown under the radar following his release from prison in 2015 until he was gunned down at the beginning of 2018.

Australian Associated Press