The father of a British fighter featured in a recruitment video for the Islamic State of Iraq and al-Sham says he wish he had never let him leave the country.
Nasser Muthana, 20, was featured in the film which calls for ‘British jihadis’ to join Isis in Iraq.
He asks: “Are you willing to sacrifice the fat job you’ve got, the big car you’ve got, the family you’ve got? Are you willing to sacrifice all that for the sake of Allah?”
Called Abu Muthanna al-Yemen in the video, Mr Muthana appeared alongside at least two other fighters who it is claimed are British and on their way to fight jihad in Iraq.
The father of Mr Muthana, who is from Cardiff, said he was “heartbroken” his son left to fight in Syria, adding that his other son, a 17-year-old, had left with him.
Ahmed Muthana, told the BBC that someone must be “driving” his sons and feared that they would “come back to me in a coffin”.
Channel 4 News has not yet been able to independently verify if the men are who it is claimed they are, and if they are fighting in Syria or Iraq.
In the 13-minute video, entitled “There is No Life Without Jihad”, the three ‘British jihadis’ say they are preparing to travel to Iraq to fight there.
The video was released by the Al-Hayat Media Centre, an organisation that has been producing slick recruitment videos for militant group Isis.
Mr Muthana told the Daily Telegraph that his elder son Nasser had been accepted at four universities to study medicine but did not go, and thinks he was “brainwashed” and radicalised in the UK.
“I wish I could hold him, hold his hand, ask him to come back,” he told the paper.
“As a father I give a message, not only to Nasser, to all the people that go from Britain to Syria to fight please stop. Come back home.”
Sir Peter Fahy, who leads the Prevent counter-terrorism strategy for the Association of Chief Police Officers, said about 500 Britons had travelled to Syria and Iraq – a higher estimate than the 400 claimed by Foreign Secretary William Hague.
He said there was “a huge amount of effort going on” abroad and in the UK to identify people who may have left for the two countries and to bring them back, but admitted “we have to be honest and say we don’t absolutely know” how many Britons have gone.
Prime Minister David Cameron has said “everything that can be done is being done” to stop Britons being radicalised overseas.
In the video claims are made that Isis also has fighters in Bangladesh, Cambodia and Australia, and two people who are said to be Australian also talk in the video.
Isis is estimated to number up to 20,000 fighters and about half are thought to be foreign fighters.