Alen Moradian, 48, was shot dead in June while sitting in his car near the busy Bondi Junction shopping precinct, sparking a spate of tit-for-tat shootings and gang violence across Sydney.
Detectives on Monday arrested two men, aged 27 and 28, during dawn raids in southwestern Sydney.
Both are expected to be charged over their involvement in Moradian's murder, police said.
Task Force Magnus detectives have arrested two men over the fatal shooting of Alen Moradian.
It comes five weeks after detectives charged the alleged "mastermind" of the shooting, which they believe was motivated by an outstanding $500,000 debt to an organised crime entity.
The 42-year-old man was arrested at the same time as another man, 31, accused of helping to co-ordinate the brazen daylight attack.
Both men are charged with murder and cannot be named for legal reasons.
At the time of those arrests, police said they were still looking for who pulled the trigger.
Nicknamed "Fathead", Moradian was arrested in 2007 along with his wife Natasha Youkhana and others over what police at the time called one of the largest cocaine and money laundering rackets in NSW history.
Moradian was sentenced to 16 years and nine months in jail for importing and supplying cocaine.
During the trial the court was told Moradian and Youkhana lived a life of luxury, using drug money to buy property, designer furniture, jewellery, a wedding reception, luxury travel and accommodation.
An email showed Youkhana urging her husband to be more like "Tony Soprano", for fear their over-the-top lifestyle would result in them getting caught.