Hayan Chandab, 35, who is a senior member of the Comanchero outlaw motorcycle gang, was shot five times by a masked gunman at close range outside his St Marys home in July 2013.

On Thursday, police were investigating another shooting - the killing of Mehmet Yilmaz, 29, at St Marys last year - when they carried out pre-dawn raids at Blackett, Meadowbank, Mount Druitt, Stanhope Gardens, St Marys and The Ponds.

Mr Chandab was arrested during a simultaneous raid at St Marys, where police searched industrial units and a car as part of an unrelated Firearms Prohibition Order.

Under the order, Mr Chandab is not allowed to own a gun or ammunition and police are permitted to search his property or car at any time without a warrant.

Officers from Strike Force Raptor, part of the gangs squad, allegedly found a loaded Smith & Wesson .357 Magnum revolver, as well as more than 500 grams of cocaine, a bulletproof vest, drug paraphernalia, steroids, and the anti-anxiety drug Alprazolam, better known as Xanax.

Police allegedly discovered someone had been living in one of the units, which had been modified by means of unlawful construction.

Mr Chandab was charged with seven offences, including possessing a prohibited weapon, possessing a loaded firearm and possessing a prohibited drug over the steroids. Police continue to investigate the cocaine allegation.

On Friday afternoon, Mr Chandab faced Penrith Local Court, where he was granted strict bail on the condition he surrenders his passport, pays a $15,000 surety and reports to police once a day.

Mr Chandab's arrest came as eight men were charged in relation to the kidnapping and murder of Mr Yilmaz, who was gunned down as he left the home of Mr Chandab's brother.

Mr Yilmaz was walking towards his car and his waiting fiancee just after 7pm on September 9, 2016, when another car pulled up and he was sprayed with bullets.

One of the gunmen then jumped out and shot at Mr Yilmaz as he lay in the gutter.

Speaking at the time, Mr Chandab said Mr Yilmaz was his "mate" and a "good guy".

Abuzar Sultani, 28, Joshua Baines, 25, and Adam McNamara, 31, are charged with murder, while Jared Prakash, 25, Siar Munshizada, 28, and Aram Makinadjian, 28, are charged with being an accessory after the fact to murder.

Mr Baines, Mr Munshizada and Mr Sultani are also charged with murdering crime figure Pasquale Barbaro, who was shot dead as he sat in a car in Earlwood in November 2016.

Erkan Keskin, the alleged head of the Lone Wolf bikie gang, is charged with kidnapping Mr Yilmaz six weeks before he died.

He was granted bail at Sydney's Central Local Court on Thursday, to enable him to prepare for a trial in Queensland.

Ergul Cakmakkaya, 46, is also charged over the kidnapping of Mr Yilmaz.

On Thursday, NSW homicide squad commander Detective acting Superintendent Jason Dickson said the gangs squad had been working with the homicide squad to investigate Mr Yilmaz's death and "suppress further acts of violence".

"Detectives are continuing to explore links between a number of shooting murders, which include OMCG [outlaw motorcycle gang] members and their associates," he said.

"Each investigation has current and active lines of inquiry. We are not giving up; it's only going to be a matter of time before arrests are made."