No stranger to prison: Farhad Qaumi.

No stranger to prison: Farhad Qaumi. Photo: Daniel Shaw

Behind bars may be the safest place for Farhad Qaumi.

The alleged leader of the notorious Brothers 4 Life gang was shot in the shoulder 10 days ago, part of what police believe is a deadly internal power struggle involving several shootings in recent months.

Then on Thursday, Mr Qaumi was arrested over a string of drug supply and firearms offences following co-ordinated raids by the Middle Eastern Organised Crime Squad on properties in Sydney and on the central coast.

Police say Mr Qaumi, 31, and his brother Mumtaz Ahmed Qaumi, 29, are leaders of the Blacktown chapter of Brothers 4 Life, a criminal group founded by convicted murderer Bassam Hamzy, who is serving a 22-year sentence in Goulburn's Supermax jail.

It is alleged that since July last year, the brothers have knowingly directed the criminal activities of the faction, which has been involved in tit-for-tat violence with its Bankstown sister chapter in recent months.

At least two men have been killed and several wounded as gun-toting gangsters compete to fill the power vacuum created by the arrest of kingpin Mohammed Hamzy over the October 2012 murder of fellow gang member Yehyah Amood. Mr Hamzy, 28, was one of a dozen members arrested in November last year.

Police Deputy Commissioner Nick Kaldas said those arrests, combined with this week's raids, have halved the size of the gang.

''Our sense is that the numbers are certainly small and shrinking by the day,'' he said. ''Speculation that this is the end of the group is probably premature. While these are significant arrests, this is not the end.''

The heavily tattooed Mr Qaumi is no stranger to prison, having previously been charged with three murders, although he was never convicted over those deaths.

And he would have known he was a marked man after receiving a gunshot wound to his shoulder when at least 18 bullets were fired at the 32-metre motor yacht Oscar II as it pulled into Rose Bay wharf about 11.30pm on New Year's Day.

For months, police have been frustrated by the refusal of people involved in the violence to co-operate. But the walls of silence are gradually breaking down, Mr Kaldas said. ''We pretty much know what has happened with just about all of the shootings that have occurred in Sydney in the last 12 months,'' he said.

The Qaumi brothers did not apply for bail in Wyong Local Court and it was formally refused. They will reappear in Central Local Court next month.