A former Home Office terrorism adviser has claimed UK authorities are tackling the terror threat in the wrong way, which is contributing to the radicalisation of young British Muslims.
He claims there are far too many arrests and most of those detained are never charged or convicted.
His assertion is in part supported by a Sky News-commissioned analysis of arrest statistics, which reveals two-thirds of those detained under terror legislation last year were never charged with a terrorist offence.
Of 289 terrorism-related arrests in 2014, just 102 were later charged with a terror offence – 35% of the total detained.
The Royal United Services Institute (RUSI), which analysed the figures, said the arrest-to-charge ratio for terrorism offences is “substantially lower” in comparison to the charge rate for all criminal offences (58%).
Mr Mahmood said the trauma and stigma associated with being detained and accused of terrorism often alienates those people and can send some down a path towards violent extremism.
He believes the government is misrepresenting the severity of the threat facing the UK, which in turn puts pressure on the police to move in and arrest individuals, even though they might have little in the way of evidence that an offence has been committed.
He said: “There are simply too many arrests. I put that down to the legislation, but also because of this constant talk about the threat level being severe. That creates this atmosphere of fear.
“Not just fear within the community, but fear within the counter-terrorism units around the country – a fear of not doing enough on time, which sometimes means they act without taking due process into consideration.
“This leads to individuals being pulled up on really very flimsy evidence, only to be later released.”
He added: “The implications of getting it wrong can only further radicalise some individuals and that’s the worry.”
Looking at the arrest statistics, RUSI said: “The number of arrests is often quoted as an illustration of the scale of the threat. However, it more accurately demonstrates the scale of police activity in countering it.
“Charge or conviction data would be a better measure of the level of confirmed terrorist activity.”
Waris Ali was just 17 when he was arrested at his home in Dewsbury, West Yorkshire, accused of downloading and possessing terrorist documents and ingredients which could be used to make explosives.
The authorities were convinced he posed a genuine threat to the public, but at his subsequent trial, a jury took just three hours to clear him of all charges.
That was seven years ago and the 25 year old is still very bitter about his treatment by the authorities, which included months of youth detention and 24-hour house arrest.
He told Sky News many young British Muslims are being targeted by the authorities for expressing the kind of views that would once have fallen under the category of freedom of speech, but which no longer seem to be tolerated.
“There are many politically engaged Muslims – you see them on TV,” said Waris. “But you see those same Muslims being smeared and labelled and being called an Islamist or terrorist sympathiser – even Jeremy Corbyn has been called a terrorist sympathiser by the Prime Minister.
“We need to have a more open and honest dialogue and discussion about the issues, rather than attacking people because of their faith. We need to actually listen to their arguments.
“If I can’t go to the mosque and talk about these issues, if I can’t talk about it at the workplace, if I can’t talk about it at university, if I can’t talk about it in the media, where exactly are people supposed to talk about these issues? Where exactly are people supposed to go?
“Is it any wonder that young Muslims who want to be politically engaged are being alienated.”
For the police, it is a difficult path to tread. Senior officers say the need to disrupt potential terrorist activity quickly can often mean they struggle to gather enough evidence to put before the courts.
Scotland Yard said it was working on 600 terror-related investigations and was making an average of one arrest per day.
A statement added: “We work proactively and positively to prevent attacks and other terrorist offences, and may exercise a power of arrest during that process if it is necessary to do so in order obtain evidence.
“This may be the only way to find out that a person should no longer be suspected of committing an offence or to understand the need to refer them for further support or to confirm that there is evidence that offences have been committed.
“Any arrest as part of a counterterrorism policing investigation is carefully considered and only made if it is necessary, usually with senior officer oversight.”
The Home Office responded by saying public safety must come first.
“At a time of such significant threat, it is only right that our police, security and intelligence agencies take all necessary steps to protect the British public,” a statement said.
“At the same time we are working in partnership with local groups and communities to challenge those who spread hatred and intolerance.”