In the first ever terror attack inside a UK jail, Hockton, 27, and his accomplice, Brusthom Ziamani, 26, attempted to stab to death “kind and helpful” Neil Trundle at HMP Whitemoor, Cambridgeshire, on January 9 2020.

They planned it in advance, crafting makeshift weapons from twisted metal with fabric-covered grips, fake suicide vests and a martyrdom letter.

Ziamani was five years into a 19-year sentence for a 2014 plot to behead a soldier, inspired by the murder of Lee Rigby. Hockton was three years into a 12-year jail term for an unprovoked stabbing attack and concurrent 10-year sentence for wounding a fellow prisoner.

Weeks before the attempted murder in Whitemoor, Hockton – or someone operating the site on his behalf – uploaded an image boasting how he would be leaving prison, saying: “2026 Soon Home. Whitemoor living.”

Despite this previous posting, a Facebook site in his name was still live last week. “Inbox me all your details and I will send you some Xmas money, bro,” said one post.

‘State institution being humiliated’ by Baz Hockton Facebook posts

Professor Ian Acheson, a former prison governor and government adviser on extremism in jails, said: “Here is another example of a state institution being humiliated by failing to notice what purports to be a convicted terrorist offender who almost killed a prison officers being able to operate online.

“If he is able to operate a phone, it is another catastrophic system failure. This is one of the most iconic and dangerous offenders who almost carried out the first ever terrorist murder of a prison officer in Britain.

“How are they allowing him access to a Facebook site? And why is a platform like Facebook allowing him to brazenly boast about his exploits?”