The former professional gambler, from Canary Wharf, spent his 54th birthday in solitary confinement for his own protection last week after somebody put a bounty on his head.
Jason was spirited off his wing at HMP Oakwood after the unknown man offered £10,000 to have him stabbed.
“We take threats to prisoners very seriously and put appropriate safeguarding measures in place,” said G4S, which runs HMP Oakwood.
The planned hit came just weeks after a “sinister” attempt to frame Jason for planning a fictitious prison break.
Both incidents closely followed a TV report by BBC London News about Jason challenging his murder conviction with fresh evidence uncovered by this newspaper.
The investigation into the hit was originally handed to police in Staffordshire, where Jason is serving a life sentence for a murder he insists he did not commit.
It has now been taken over by Essex Police – but the reason for that is unclear.
Family members claim this is the third time an attempt to overturn Jason’s conviction has provoked a threat of violence.
When he launched an appeal in 2017, his girlfriend said she received an Osman warning from the police, informing her of a credible threat to her life. The Met Police did not dispute this claim when we put it to them.
Then Jason’s sister Kirstie claimed she was threatened with acid when an application was made to the Criminal Cases Review Commission (CCRC) in 2020.
That application was unsuccessful, but a new one was submitted in November 2023.
“Every time it looks like this case might be reinvestigated, somebody starts making threats,” said Kirstie.
“Somebody somewhere obviously doesn’t want this case looked at carefully again.”
Jason is serving life after being convicted in 2013 of murdering Robert Darby, from the Isle of Dogs, by stabbing him to death outside the Valentine pub in Gants Hill, Ilford.
But Robert’s family believes it was a miscarriage of justice and is actively involved in trying to overturn Jason’s conviction.
He was charged after a single eyewitness identified him as the stabber – but a two-year investigation by Newsquest uncovered problems with the witness’s account.
Approached by this newspaper, he admitted he had been “drunk” when he saw Robert attacked and might have identified the wrong person.
That interview has been submitted to the CCRC in the hope of securing a fresh appeal.
The new application was the lead story on BBC London News on November 28.
Around two weeks later, a suspicious package was sent to Jason at HMP Oakwood, marked as legal correspondence.
When the prison checked it, it contained details of a supposed escape plan and a handcuff key.
But an investigation by the prison’s security team concluded that there was no escape plot and Jason posed no risk of escape.
The prison referred the incident to the police.
“A prison officer told Jason it was a very sinister attempt to get him in trouble, that it was obviously someone who knew the prison system and he doubted it would be the last of it,” claimed Kirstie.
Police were already investigating the prison break hoax when the hit was ordered in late December.
“We have liaised with HMP Oakwood regarding the safeguarding of the prisoner,” said Staffordshire Police.
“The investigation is being managed by Essex Police.”
An Essex Police spokesperson confirmed: “We are investigating an allegation of threats made against an individual following a referral by colleagues with Staffordshire Police.”
Book, Life Inside” alt=”Echo: Bestselling crime writer Linda Calvey has included a tribute to Jason Moore in her new book, Life Inside” class=”editor-image” style=”aspect-ratio: 2400 / 1600;”/>
Supporters of the Free Jason Moore campaign include cricket legend Sir Ian Botham, bestselling crime author Linda Calvey and the Bishop of Stepney, who has protested against Jason’s conviction outside Downing Street and organised a special church service in Poplar last month in his honour.
Attendees included Jason’s family and Robert’s brother Tim, from Havering.
Catch up on our exclusive investigation into Jason Moore’s murder conviction: