A man who was once linked to an IS terror cell nicknamed the Beatles has pleaded guilty to charges of possessing a firearm for terrorist purposes and funding terrorism.
Aine Davis, 39, appeared at the Old Bailey via video link from Belmarsh Prison on Monday.
He has already served a prison sentence in Turkey for being a member of the Islamic State group and was arrested on arrival back in the UK last August.
Davis will be sentenced on 13 November.
At one point he was suspected of being a member of the gang who were called the Beatles by their captives.
There has been no attempt to put Davis on trial for being a member of the kidnap gang either in the UK or the US, even though at one point the then Home Secretary Priti Patel was asking the US to extradite him and prosecute him.
The gang became infamous for videoing the beheading of their British, American and European hostages.
They were led by Mohammed Emwazi who became known as Jihadi John and who was killed by US drone strike.
Two other members of the gang El Shafee Elsheikh and Alexanda Kotey are serving life sentences in the US. All three were British.
Davis knew Alexander Kotey in West London, travelling to Turkey with him in 2012. He also knew Mohammed Emwazi.
Since being charged last year Davis argued through his legal team that he should not face trial in the UK as he had already served a sentence in Turkey for what amounted to the same offending.
But Mr Justice Mark Lucraft KC and the Court of Appeal ruled against him.
He has now pleaded guilty to possessing a firearm for the purposes of terrorism after sending a picture of himself holding a rifle in Syria to his then wife Amal El-Wahabi. He also admitted two charges linked to funding terrorism.
Extremism
Before leaving the UK for Syria Davis was a drug dealer who carried a gun. He was jailed for possession of a firearm in 2006.
He converted to Islam but was soon embracing violent extremism, and by the time the Islamic State group declared its caliphate in Syria 2014, Davis was there. He had left behind his wife Amal El-Wahabi and two children travelling to Syria via the Netherlands and Turkey in July 2013.
He first came to public attention when Amal El-Wahabi was found guilty at the Old Bailey in 2014 of sending him money for the purposes of terrorism. It was at that trial that the image of him with a group of men in Syria all holding guns first emerged.
In November 2015 Davis was arrested in Turkey during a raid on a safe house in the coastal town of Silivri. The house was often used by men crossing the border in and out of Syria. He was arrested on the same day that Mohammed Emwazi was killed by a drone strike in Syria.
He was convicted of being a member of the Islamic State group in a Turkish court in 2017, and sent to prison.
When his prison sentence came to an end he was deported to the UK. But the then Home Secretary Ms Patel had been in touch with prosecutors in the US apparently trying to persuade them to pursue a case against Davis.
When this did not happen, Davis was arrested on arrival at Luton Airport.