Former inmate Mick Parker, who worked with Massey in the prison gym and was freed earlier this month, told The Sun: "For John to have gone over the wall the way he did, help will have had to have been involved.
"He got a parole knock-back and had the raving hump. Obviously, he put a plan into action."
Massey, who is one of Britain’s longest-serving prisoners, received a life sentence for shooting a man dead with a sawn-off shotgun at a pub in Hackney, east London, in 1975.
The convicted killer’s escape will raise embarrassing questions for the prison authorities given his history of absconding.
He was freed from jail in June 2007 after serving his time for murder, but breached his parole conditions so he could be with his dying father for his final days.
He was immediately recalled to jail but after two-and-a-half years he was decategorised and sent to Ford open prison in West Sussex.
Massey walked out of the jail in May 2010 after learning that his sister was gravely ill so he could be at her side. He was rearrested at his mother’s house 10 months later and sent to Pentonville in Islington, north London, before his latest escape.
Massey spoke in an interview this year of his frustration at still being in prison after so long: “How are the public in danger of me?
"I did not commit any crime in the time I was free and my mother's neighbours know and respect me and say I was an asset to the community."
He was reported missing from Pentonville at 6.30pm on Wednesday after fashioning a rope and evading prison officers.
A local cafe owner said: "My friend is working in the prison and he said that the guy went to the gym and then hid in the roof and waited for everyone to go. He just waited and then escaped from there."
One member of staff at Pentonville Prison said: "He's done this before, he'll be back."
Scotland Yard has advised members of the public not to approach the "potentially dangerous" offender and instead to call 999 if he is spotted.
Pentonville houses up to 1,250 category B male prisoners, described as those "for whom the very highest conditions of security are not necessary but for whom escape must be made very difficult".
Convicted arsonist Julien Chautard escaped from the same jail in 2009 by clinging to the underside of a security van.
