Police are pledging to hunt down organised crime members who masterminded the kidnapping of an elderly man, after arresting a figure accused of fatally botching the job.
Another four men have been arrested in connection with the mistaken identity kidnapping and murder of 85-year-old grandfather Chris Baghsarian, police said on Tuesday.
A 32-year-old man accused of directing the job was arrested and charged, one of 11 individuals now charged over the crime.
He was arrested in relation to a separate incident in February before further investigations linked him to the 85-year-old's death.
Robbery and Serious Crime Squad commander Andrew Marks said the man was "directly responsible".
"He attended the address. He physically kidnapped Mr Baghsarian,'' he said.
"He detained Mr Baghsarian and took him to the property in Dural."
The elderly man was taken from his North Ryde home in the early hours of February 13, sparking a major search, with police urging his kidnappers to release him.
Police believe Mr Baghsarian was killed at a makeshift stronghold in Dural, on Sydney's northern outskirts, before his body was found dumped on February 24.
Detective Superintendent Marks said it was a botched extortion attempt on behalf of an overseas organised crime network.
"We are continuing to investigate those ... who took out a contract to kidnap an elderly person - not Mr Baghsarian, but another person," he said.
"We will continue to investigate that and bring those responsible ... to be held to account."
The alleged ringleader was initially arrested in Blacktown, in western Sydney, on February 23.
During a search of the man's car, police said they seized methamphetamine and a pistol, and during a subsequent search of a property in Penrith, they found cannabis and a vehicle.
The man was charged with firearm and drug offences.
Detectives analysed photographic evidence that revealed he allegedly co-ordinated and participated in Mr Baghsarian's kidnapping and murder.
The 32-year-old was formally arrested in western NSW on July 8 and subsequently charged with murder and kidnapping offences.
A day later, police arrested a 22-year-old man at Riverstone Police Station, while on Monday officers arrested a 21-year-old man in Lethbridge Park and 19-year-old man at Mt Druitt Police Station.
The 22-year-old was charged with murder and kidnapping offences, and the two younger men were charged with being accessories to the crimes.
Those charges relate to the alleged pre-positioning of two or three vehicles before the kidnapping and murder took place.
Further minor charges might be laid against people who had knowledge of the event or who committed crimes after Mr Baghsarian's body was found, investigators said.
Eleven days after he vanished, the grandfather's body was found near a golf club in the semi-rural suburb of Pitt Town in Sydney's north-west.
Police say the elderly widower was not the intended target of the kidnap-ransom plot.
The 19-year-old man will face Mount Druitt Local Court on Tuesday, while the 32-year-old alleged ringleader and 22-year-old are both due to appear at Penrith Local Court on Friday.
The 21-year-old man had already appeared in court.
