Erkan Keskin, who is allegedly a senior member of the Lone Wolf bikie gang, was arrested in Sydney's CBD last week in connection with the alleged kidnapping of Mehmet Yilmaz last year.

Mr Yilmaz, 29, was allegedly kidnapped just weeks before he was slain in a gangland shooting outside the St Marys home of Commanchero bikie Tayan Chandab in September 2016.

Police are yet to charge anyone over the murder, which is being investigated by the State Crime Command.

"Detectives from the State Crime Command's Homicide Squad established Strike Force Estop to investigate the murder of Mehmet Yilmaz at St Marys on Friday, September 9, 2016," the police said in a statement.

"The charges relate to an alleged kidnapping of Mr Yilmaz in the weeks before his murder."

Following his arrest last Thursday morning, Keskin was charged with several offences, including kidnapping and knowingly giving misleading evidence to the NSW Crime Commission.

The 40-year-old was also charged with revealing conversations with the commission, obtaining advantage through occasioning actual bodily harm and demanding money with menaces with intent to steal.

At the time of his arrest, Keskin was already on bail for drug charges in Queensland.

The former Turkish soldier character earned the nickname the "naked bikie" in 2015, when he was arrested on a suburban street in Sydney's west, while naked and carrying a firearm.

Keskin appeared at Central Local Court on September 28 and was formally refused bail, while the matter was adjourned to October 5.

While Strike Force Estop was established to investigate the 2016 murder of Mr Yilmaz, his death is also one of eight gangland killings being investigated by Strike Force Osprey.

All eight victims involved in the killings had an organised crime association and in some cases they were known to each other.

The formation of Osprey followed the execution of underworld Mafia figure Pasquale Barbaro, who was shot multiple times in November last year.