Rigby, 25, was returning to Woolwich barracks when he was butchered to death with knives and a meat cleaver in May 2013. Adebolajo, who's been branded Britain's most dangerous prisoner, received a whole-life tariff, while Adebowale was jailed for a minimum of 45 years.

The jihadist murderers of British fusilier Lee Rigby have allegedly been battered in prison by drug baron John Anslow after he got tired of hearing them chatting loudly all night.

Anslow — currently serving a 22-year jail term for running a cocaine and cannabis distribution network — allegedly assaulted Michael Adebolajo and Michael Adebowale at high security Belmarsh prison last week.

Speaking to the Birmingham Mail, his father — also named John — told the Birmingham Mail, alleged the pair were "shouting…all night and all day", "one each side of him".

© East News / MOD / eyevine Ministry of Defence undated handout photo of Drummer Lee Rigby, 25, from the 2nd Battalion, Royal Regiment of Fusiliers who was named today as the soldier killed in Woolwich, London yesterday during a brutal attack

"One tried to put it on him and came off worst. John got him on the floor and was throwing punches before the screws pulled him off. He gave it to him. He stood his ground and had a go back. They are the worst of the worst. I'd like to do to them what they did to Lee Rigby," he said.

— darren morris (@darrren1965) June 2, 2019

​A Ministry of Justice spokesperson said such a confrontation was "unlikely" as strict conditions were in place to prevent Adebolajo and Adebowale mingling with other Belmarsh inmates — although conceded it would be almost impossible to probe the claim without knowing the date of the alleged encounter.

Anslow gained global notoriety after being sprung from a prison van taking him to court in January 2012, a masked gang armed with sledgehammers assisting his escape — the first Category A prisoner to escape since 1995. The break-out earned him an additional seven years in prison.

— Anne Harratt (@AnneAnne59) June 3, 2019

​He would spend over a year on the run, along the way taunting UK authorities via social media, before being arrested in March 2013.

Outstanding Questions

Adebolajo and Adebowale, both of Nigerian heritage and raised as Christians before converting to radical Islam, were found guilty of murdering Rigby in December 2013.

As with many other terrorist attacks in recent years, the pair were well-known to UK intelligence services in the years leading up to their bloody crime. A November 2014 parliamentary report found the two men appeared in a total seven security agency investigations.

​"There were errors in these operations, where processes were not followed, decisions not recorded, or delays encountered," the report stated.

While investigators did not rule that "any of these errors, taken individually", could've prevented Rigby's death, they conceded Adebolajo was a high priority for MI5 during two sepearate operations, with "significant effort" and a "broad range of intrusive techniques" invested in investigating him.

"The one issue we have learned of which, in our view could have been decisive only came to light after the attack. This was an online exchange in December 2012 between Adebowale and an extremist overseas, in which Adebowale expressed his intent to murder a soldier in the most graphic and emotive manner. This was highly significant," the report concluded.