A 21-year-old man has been charged with being a member of so-called Islamic State, officials from the Kurdish region of Syria have said.
Jack Letts, also known as “Jihadi Jack”, is originally from Oxford and travelled to Syria in 2014.
He was later captured by the Kurdish-led YPG, a group fighting IS, when he left IS territory.
Officials confirmed he was captured in May 2017 but Mr Letts said he is opposed to IS.
In a statement given to the BBC, the Democratic Federation of Northern Syria (DFNS) said Mr Letts had been taken to a prison in Qamishi, Rojava.
The self-declared autonomous region of Syria said the case was still under investigation by the local police force, the Asayiah.
This is also the first time Kurdish forces have confirmed the capture of Mr Letts as a prisoner of war.
Mr Letts converted to Islam while still at school in Oxford and at 18 dropped out of his A-Levels to travel to Jordan in 2014.
By the autumn of that year he was in IS-controlled territory in Syria. He then married in Iraq and now has a child.
His parents have denied he went to Syria to fight with IS and have started a petition which claims he is being held in a “Guantanamo-style black site” in Kurdish-controlled territory.
But the DFNS European representative, Sinam Mohamad, denied this.
Ms Mohamad’s statement said: “The Democratic Federation of Northern Syria’s policy with regard to prisoners of war is clear and fair.
”ISIS brought inexplicable levels of terror on the peoples of Northern Syria/Rojava…
“Despite this fact, the DFNS is not less committed than European countries to treating the fighters from this terror group according to international human rights standards.”
On the petition page it states that John Letts and Sally Lane have not heard from their son since July and do not have confirmation that he is alive.
They have said the British government has not done enough to help their son.
The DFNS statement however also stated that Kurdish officials were willing to hand over prisoners of war to their original country after being properly investigated.
It states that once the investigation is concluded “the outcome will be communicated to Jack’s parents”.
Mr Letts also has a Canadian passport and the statement goes on to suggest his parents should request the Canadian and British governments to officially request the handover of the 21-year-old.
John Letts and Sally Lane have pleaded not guilty to charges of funding terrorism after being accused of sending cash to their son.
Their solicitor has said they have declined to comment.
The Foreign Office said: “The government is unable to provide support to British nationals in Syria as the UK government does not have consular representation there.”