Jack Letts, 20, is reported to be the first white Briton to have joined the Islamic State after converting to Islam.
Now known as Ibrahim or Abu Muhammed, he travelled to Syria when he was 18 after converting to Islam, according to reports in the British media on Sunday.
According to The Times, he admitted to his parents that he had joined the IS in September 2014 and has reportedly married a woman from Fallujah, Iraq, shortly after arriving in Syria.
The reports said he came from a secular, non-Islamic background; studied at Cherwell School in Oxford. His father is said to be an organic farmer and archaeobotanist and his mother a books editor.
Both are said to be extremely worried for his safety after he told them he was moving to Kuwait to study Arabic, when, in fact, he was travelling to Syria.
One former school friend told the paper: “At school, he was very much the classroom clown and was liked by a lot of students. That’s why this whole thing of him going to live in Syria and join Isis doesn’t make any sense.”
Some former school friends from Oxford reportedly named him “Jihadi Jack”.