Exclusive: A pedophile bikie who is suspected of killing a woman in the 1990s also threatened a child abuse victim with the same fate, it is claimed.
The allegation, made on a Facebook page dedicated to missing mother Tracey Valesini, follows this masthead’s global Left in the Cold investigation, which last month revealed Comanchero bikie Arthur “Jock” Mackenzie was “intimately involved” in her death.
The social media page has been flooded with new members since the three-part multimedia series launched, claiming MacKenzie murdered the 20-year-old in the NSW Blue Mountains home they shared in 1993, as she was about to report him to police for a break and enter.
Now, it is alleged MacKenzie used Tracey’s death to “scare” women and “young children” – including another potential victim – that their life would end similarly.
A person, posting anonymously on Tracey’s page, claimed to know at least one other child he allegedly sexually abused.
The same person also wrote that Tracey’s body was disposed of in “horrible ways so no body was to ever be found”.
The post has since been deleted, however a source has verified its credibility with this masthead.
Tracey’s sister Sharon Robards is now questioning how many victims MacKenzie hurt in his lifetime and how many people protected him.
“The world now knows what a predator and coward MacKenzie was. He preyed on young women and children,” Mrs Robards said.
MacKenzie was deported from Australia in 2004 after a decade-long crime spree, which included ‘encourage to murder’ charges.
He died of health complications in a Scottish jail in 2024 awaiting sentence for sexually abusing another child at his residential home in the quiet seaside village of Carradale.
The assault victim – who cannot be identified – was grieving the death of her mother at the time she was attacked.
A 15-person jury took just 39 minutes to unanimously convict MacKenzie of the crime, after a five-day criminal trial at Scotland’s Campbelltown Sheriff Court.
MacKenzie had spent three months in HMP Low Moss prison on the outskirts of Bishopbriggs, East Dunbartonshire, near Glasgow, before his death.
The last known sighting of Tracey, a mother of two, was at a court hearing in Campbelltown, Sydney, on January 8, 1993.
On February 12 she failed to appear at another hearing.
But more than a year later a cheque for $500 was deposited into Tracey’s St George Bank account at Liverpool in December 1994.
About four days later $490 was withdrawn from her account in Springwood in the Blue Mountains.
The person behind the mysterious transaction had Tracey’s bank card and knew her PIN.
It is believed Tracey was already dead as there were no other withdrawals or activity on the account in the months preceding the suspicious transaction.
At the 2006 inquest into Tracey’s disappearance, Coroner J Abernethy ruled: “Tracey Leanne Valesini died between December 1992 and December 1993, at Wentworth Falls of injuries inflicted upon her by another person. As to the identity of that person, the evidence adduced does not enable me to say.”
Police believe she was shot dead inside the Blue Mountains home she shared with MacKenzie, William Booby – her bikie boyfriend at the time – and his sister Dianne Booby. Dianne and MacKenzie were married at the time.
The Left In The Cold – Finding Tracey Valesini – investigation also revealed the police theory behind her murder for the first time.
In a police brief, obtained exclusively by this masthead, detectives believe she was killed because she was about to go to police about a violent armed robbery masterminded by MacKenzie.
Some answers to the mystery are contained in the statement of Detective Sergeant Steven Trevitt, tendered to the 2006 inquest.
Police believe MacKenzie was responsible for a break and enter in Sydney’s west when armed offenders tied up another innocent woman at gunpoint.
The armed robbers stole a safe containing three firearms and cash from the western Sydney home of licensed security guard Ian Cager, the brother of Tracey’s former partner Scott Cager.
“Police believe that it is likely that Tracey was murdered resulting from a disagreement with MacKenzie pertaining to the Cager home invasion,” Sergeant Trevitt’s statement reads.
Mrs Robards believes she also could have been killed for accusing MacKenzie of pedophilia.
When Tracey disappeared, none of her housemates, including Mackenzie and her boyfriend, reported her missing.
MacKenzie, Dianne Booby and her brother William are all considered persons of interest in that they may be witnesses to events that occurred prior to Tracey’s disappearance.
Police claimed that an informant told them William told a relative that Tracey was shot dead by MacKenzie in the bathroom of their sharehouse.
“‘Jock’ shot her because she was going to the police, so he shot her … there was blood everywhere, all over the bathroom and they spent all day cleaning it up,” the police statement read.
In 2001, a forensic search found small amounts of blood in the bathroom in question.
William Booby and Dianne Booby were not available for comment.
