Seven terrorism suspects still considered a threat to UK national security have had special measures designed to restrict their movement and monitor their communications lifted.
The suspects, who cannot be named for legal reasons, were placed under Terrorism Prevention and Investigation Measures (TPIMs) after falling under suspicion of involvement in planning attacks.
Under the measures, the suspects were fitted with electronic tags, their telephone and internet use restricted and they were banned from associating with certain individuals.
The measures were introduced to replace the previous government's Control Orders, which were criticised as too draconian, and which allowed law enforcement officials to monitor individuals who could not be proved to have committed an offence.
TPIMs expire after two years, and the suspects are now free after authorities offered no new evidence justifying the renewal of the measures.
'A partial solution'
Raffaello Pantucci, a terrorism expert at the Royal United Services Institute, told Sky News that TPIMs were only ever a partial solution to a complex problem.
"The underlying problem of what to do with individuals who are clearly of concern to the security services but have not crossed the criminal threshold, how to address these sorts of people, was never really fundamentally addressed," he said.
At a court hearing recently, Home Secretary Theresa May said the seven were still a danger, and that steps would be taken to reduce the risk they pose.
One of the suspects, known as CD, was described as "determined to carry out a Mumbai-style attack in Britain".
He is alleged to have attended a terrorist training camp in Cumbria in 2004 with four of the five men who launched a suicide bombing attack on London Underground after 7/11.
TPIMs have been criticised by human rights campaigners for being a milder version of Control Orders, and criminalising individuals who had not been shown to have committed an offence.
The government has defended the measures, and claimed TPIMs had proved "effective in reducing the national security risk posed by a number of individuals".
Security minister James Brokenshire said: "It is not possible to discuss individual cases, but the police and security services have been working for some time to put tailored plans in place to manage the risk posed by these individuals once their TPIM restrictions are removed.
"These plans, which are similar to those put in place for the release of prisoners who have served their sentences, are kept under constant review."
A judicial committee charged with assessing anti-terror legislation has said that the orders do not serve any investigative function and their nature "carries an inherent risk of the subject absconding".
In November, Mohammed Ahmed Mohamed, who was under a TPIM after been linked with Somalian terrorist group al-Shabaab, went missing after leaving a west London mosque wearing a burka.
Police are still searching for him.