An Islamist extremist serving a life sentence for plotting to bomb the UK's Bluewater Shopping Centre helped to inspir other terrorists while in jail, security sources claim.
Anthony Garcia, 38, was jailed in 2007 for planning to detonate a bomb at the shopping centre in Kent.
He is serving his sentence at HMP Full Sutton in East Yorkshire and is believed to have influenced the militants behind the 2019 London Bridge terrorist attack and the Reading terrorist attack.
Security sources told The Times newspaper that he has influenced former gang members and murderers who had no interest in religion before entering the prison system.
They claim he held “a leadership role” because of his links to London's July 7 Tube bombers and having attended an Al Qaeda training camp.
A London gang member who spent time in prison with Garcia told The Times he conducted fitness training with groups of prisoners.
“He used to do circuit training with his group on the wing," he said.
"He used to hold lectures in his cell. Sometimes he would record them on a mobile phone and distribute them to other prisons. He also translated [ISIS] lectures."
Garcia was under surveillance when he met the London Tube bombers.
He was later caught after buying 600 kilograms of fertiliser in a plot to blow up nightclubs and shopping centres.
The Ministry of Justice said it has trained nearly 35,000 officers to spot the signs of extremism and increased the number of counter-terrorism staff.
"We will separate the most subversive prisoners from the general population where necessary," it said.
Jonathan Hall, QC, the independent reviewer of terrorism legislation, is investigating extremism in prisons.
“I cannot discuss individuals but what is striking is the ability of some terrorist offenders to occupy heroic status in the prison gang," he told the newspaper.
"These gangs then act as a vector for the power and influence of terrorist offenders. At worst, this leads to specific acts being encouraged."