A close relative of Jack Letts has cited "an avalanche of misinformation" written about the 20-year-old, dubbed "Jihadi Jack" by the media, adding that it was a "right wing" media conspiracy as they dubbed Letts the first white British youth to join Isis in Syria.

"There has been an avalanche of misinformation. We don't want to comment on all of this, but what I will say is that 95 per cent of what has been published is incorrect, it is desperately wrong," the family member was quoted as saying by The Telegraph.

"The only truth is that Jack is a Muslim and he is overseas. But everything else is made up and it is just getting worse," the person added. The media was only "interested in a snappy line like "Jihadi Jack" or "Jihadi John" that "rolls off the tongue", the family member said.

According to reports, Letts was 18 years old when he secretly travelled to Syria to join Isis, while informing his parents that he was headed to Kuwait to study Arabic. Letts was in the Syrian city of Raqqa before moving to the Iraqi city of Fallujah, where he is believed to be a front-line fighter for Daesh, The Daily Mail reported. He reportedly has an Iraqi wife and son named Muhammed.

Before travelling to Syria, Letts converted to Islam and changed his name to Ibrahim. He is also known by the name of Abu Muhammed. His school friends said that before Letts converted to Islam, he used to drink beer and occasionally smoke cannabis. Letts was described as a talented student and keen Liverpool FC supporter.

Letts attended the Madina Masjid near his home in Oxford, but was radicalised in secret prayer meetings at a mosque. "He told me he had started visiting a Wahhabi mosque. I believe he started going there with his classmates and I knew this could be bad as Wahhabi is not Islam, it is very bad," one female neighbour, also a Muslim, said.

"I spoke with his father who became very worried when he converted to Islam. I sat with him and told him not to worry. To hear that he has gone away to Syria brings me utter sadness. I feel very depressed, and I feel bad for him," she said.

"His father was very depressed when we last spoke, it must be terrifying for him to have a son going into a war zone," she said. "I fear Jack has been brainwashed," she said.