He was speaking after a former Home Office adviser on terrorism claimed that too many people are being arrested for terrorism offences, and most of those detained are never charged or convicted.
Jahan Mahmood quit his job and said that he believes this could be leading to the radicalisation of British Muslims.
Simon Barrett told Premier's News Hour that these people on the edge of extremism "May feel that they're inconvenienced, they may feel that they're being monitored by security services, monitored by the police force and they may feel that this causes destruction and they may think this causes discrimination against them.
"But on the whole, the security services need this because maybe they have one interview or one discussion with one young, impressionable British Muslim, who's interested in ISIS or interested in jihad but hasn't made that leap to actually go and join ISIS out in Syria or Iraq or to become a terrorist.
"Therefore that provides vital information for our security services and police force and government to know who's been radicalised, who's radicalising them and what group they're associated with - so they can get the bigger fish rather than the smaller fish."
Figures show that two-thirds of terrorism-related arrests in the UK do not result in suspects being charged and in 2014 289 people were detained on suspicion of terrorism offences, 102 went on to be charged.
The number of 18 to 20-year-olds arrested more than doubled on the previous year from 20 to 43, while those aged over 30 increased by a third.
35 suspects were female, the highest number on record and more than three times higher than five years ago and eight suspects were minors.
The Home Office said the first duty of the Government was to keep people safe and a spokesperson said: "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.
"At the same time we are working in partnership with local groups and communities to challenge those who spread hatred and intolerance.
"And this Government will do everything possible to make sure they have the powers, the capabilities and resources they need."
Listen to Premier's Antony Bushfield speak to Simon Barrett here:
