This story has been published by the BBC on its website HERE It will be of interest to readers following the public meeting on Prevent last week and the subsequent meeting with Brent Council
Its Policing and Crime Committee called for more transparency around implementation of the government's Prevent strategy.
Cooperation between boroughs was "patchy" and the police needed to step back if the public were to have more confidence in the scheme, it found.
The Met has been approached for comment.
Under Prevent, which aims to stop people supporting or becoming terrorists, local authorities have a statutory obligation to monitor signs of extremism in schools and public services.
But the committee said this was proving a "challenge" for teachers, and some young people were afraid to take part in discussions about extremism for fear of being "put on a list".
The committee echoed previous criticisms of Prevent, when it was dubbed a "toxic brand" which aroused suspicion among communities.
"We know that community engagement is hampered by suspicion and fear, and much of this is the consequence of the secrecy that surrounds the delivery of the Prevent strategy."
Committee chairwoman Joanne McCartney said "a strong counter-narrative which condemns violent extremism" was one of the most powerful ways to counter online radicalisation, "but attempts to deliver this have been lacking so far."
Through social media, groups such as the so-called Islamic State (IS) were "telling a better story" in a fight where "narrative is actually almost everything", Lord Carlile of Berriew said.
In the capital, Counter-Terror Local Profiles, which set out risk in a particular area, are highly confidential documents often only seen by a borough commander and council chief executive.
In Birmingham and Manchester, the information is shared with public services "without giving away anything of national security importance".
Communities in London should have a say in how best to prevent extremism, and the police should only intervene when necessary, according to the report.
It criticises 'patchy' co-ordination between London boroughs.
"There appears to be no London body that has overall oversight of what is taking place at any one time," it said.
"It is difficult to establish what, why and how decisions have been taken in respect of preventing extremism."
In some boroughs, such as Waltham Forest, the quality of work was "extremely high", Lord Carlile told the committee. In others, it was "rather less high".
Secrecy surrounding anti-terrorism work is hampering efforts to halt extremism, the London Assembly has said.
Cooperation between boroughs was "patchy" and the police needed to step back if the public were to have more confidence in the scheme, it found.
The Met has been approached for comment.
Under Prevent, which aims to stop people supporting or becoming terrorists, local authorities have a statutory obligation to monitor signs of extremism in schools and public services.
But the committee said this was proving a "challenge" for teachers, and some young people were afraid to take part in discussions about extremism for fear of being "put on a list".
'Narrative battle'
"For the public, transparency about what Prevent is for and what activity is taking place is critical," it said.The committee echoed previous criticisms of Prevent, when it was dubbed a "toxic brand" which aroused suspicion among communities.
"We know that community engagement is hampered by suspicion and fear, and much of this is the consequence of the secrecy that surrounds the delivery of the Prevent strategy."
Committee chairwoman Joanne McCartney said "a strong counter-narrative which condemns violent extremism" was one of the most powerful ways to counter online radicalisation, "but attempts to deliver this have been lacking so far."
Through social media, groups such as the so-called Islamic State (IS) were "telling a better story" in a fight where "narrative is actually almost everything", Lord Carlile of Berriew said.
'No oversight'
The committee said London could learn from Birmingham's success in co-ordinating Prevent.In the capital, Counter-Terror Local Profiles, which set out risk in a particular area, are highly confidential documents often only seen by a borough commander and council chief executive.
In Birmingham and Manchester, the information is shared with public services "without giving away anything of national security importance".
Communities in London should have a say in how best to prevent extremism, and the police should only intervene when necessary, according to the report.
It criticises 'patchy' co-ordination between London boroughs.
"There appears to be no London body that has overall oversight of what is taking place at any one time," it said.
"It is difficult to establish what, why and how decisions have been taken in respect of preventing extremism."
In some boroughs, such as Waltham Forest, the quality of work was "extremely high", Lord Carlile told the committee. In others, it was "rather less high".