Radical preacher Anjem Choudary, jailed for inviting support for the Islamic State group, has been released.
Anjem Choudary: Radical preacher released from prison
The cleric was sentenced in 2016 to five-and-a-half years in prison.
He led an extremist network linked to violent jihadists, including one of the killers of soldier Lee Rigby in 2013.
Choudary, 51, has now served half of his sentence and will complete the rest under strict supervision. Police are preparing up to 25 measures to control him, the BBC understands.
Who is Anjem Choudary?
Mr Choudary, from Ilford in east London, once headed up the al-Muhajiroun network - a leading extremist group which was banned under terrorism laws.
He did not organise terror attacks, but is considered one of the UK's most dangerous radicalisers.
He has been described as a "hardened dangerous terrorist" and someone who has had a "huge influence on Islamist extremism in this country" by former Met Police terror chief Richard Walton.
Why is he being released now?
When an offender is released at the midway point of their sentence, the rest is spent in the community "on licence".
He will not be free but must comply with a list of conditions. If he breaches them, he risks being recalled to prison.
How will he be monitored?
Police and MI5 are expected to be among several agencies monitoring Choudary, after his release on Friday morning from Belmarsh prison.
He will be placed in a probation hostel for six months, the BBC understands. The conditions he must obey include:
A ban from preaching at or attending certain mosques He will only be allowed to associate with people who have been approved by the authorities He will be allowed one phone and is banned from using an internet-enabled device without permission Use of the internet will be supervised He will not be able to leave the UK without permission.
Earlier this week, it was announced Choudary had his assets frozen and was listed on a global record of known terrorists. overseen by the United Nations Security Council.
The asset-freezing order means he will be under extremely strict financial controls which typically mean the authorities will be alerted if he tries to open a bank account or move money.
Prime Minister Theresa May said on Thursday that authorities including the police, prison and probation service have "significant experience in dealing with such offenders".
Analysis: What impact has Choudary's sentencing had?
By BBC home affairs correspondent, Dominic Casciani
When Choudary was charged in 2015 with inviting support for IS, it was a moment of great success for counter-terrorism chiefs - and they were already trying to build cases against other associates.
Some, including close confidantes, were jailed. At least four others, who cannot be named for legal reasons, were subject to a Terrorism Prevention and Investigation Measure (TPim), a form of control that places two years of restrictions on the movements and activities of terrorism suspects who have not been charged with a crime.
Detectives also looked for evidence of standard crimes - such as fraud - as a means to further "disrupt" the network.
The insider view is that this work has been generally successful because it made the targets aware they could no longer act with impunity.
In theory, it created space for the security service MI5 and their police detective colleagues to focus on more urgent threats.
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