New laws are needed to ban possessing extremist propaganda, the chief coroner said today in a report following the inquests into the London Bridge terror attack.
Mark Lucraft QC said a gap in legislation means it may be impossible for police or MI5 to act even when 'the material is of the most offensive and shocking character'.
He highlighted 18 'matters of concern' in a report on preventing future deaths, which was published today after inquests into the deaths of eight people on the evening of June 3 2017, and their attackers.
Police officers walk down Borough High Street following the terror attack on June 3, 2017
Khuram Butt, 27, Rachid Redouane, 30, and Youssef Zaghba, 22, were ruled to have been lawfully killed after they were shot dead by armed police
They ploughed a rented van into pedestrians on the bridge before stabbing people at random around Borough Market.
A separate inquest concluded that Xavier Thomas, 45, Chrissy Archibald, 30, Sara Zelenak, 21, James McMullan, 32, Kirsty Boden, 28, Alexandre Pigeard, 26, Sebastien Belanger, 36, and Ignacio Echeverria, 39, were unlawfully killed.
The Old Bailey inquest heard that Butt, who was an MI5 subject of interest (SIO), had looked at extremist material online in the months and years before the attack, including propaganda for so-called Islamic State, violent images and sermons from extremist preachers.
Bereaved families said MI5 and counter-terror police should review their assumptions about the weight placed on an SIO's so-called mindset material.
Emergency services at the scene of the London Bridge and Borough Market attack in 2017
Mr Lucraft said there is no evidence investigators are not capable of making those judgments properly after police and security services pointed out that many SIOs possess such material.
But he suggested new laws could be introduced to tackle the prevalence of extremist material in the same way legislation has criminalised the most offensive pornography.
He said: 'While there are offences of possessing a document likely to be useful to a person in committing an act of terrorism (section 58, Terrorism Act 2000), and of disseminating terrorist publications (section 2, Terrorism Act 2006), there is no offence of possessing terrorist or extremist propaganda material.
'It may be impossible to take action even when the material is of the most offensive and shocking character.
'The evidence at the inquests indicates to me that the lack of such an offence may sometimes prevent counter-terror police taking disruptive action which could be valuable in their work of combating terrorism.
An armed police officer on London Bridge as officers deal with the terror attack in June 2017
'I have formed the view that