In an interview last week with British Channel 4, the grandfather Henry Dare, 59, said that the boy in the video is Isa Dare, the son of his daughter Grace "Khadijah" who converted to Islam and fled to Syria to fight for Islamic State.
Dare said he recognized Isa when he appeared at the end of the 11-minute clip: "I can't disown him, he's my grandson. I know him very well," he stated. The claim that the boy was indeed his grandson has not received official approval.
The boy seen in the clip saying "We are going to kill the kaffir (non-believers) over there," while pointing towards the UK, has already appeared in ISIS propaganda. In photos that circulated on social networks last year he was seen holding a Kalashnikov rifle.
"He does not know anything, he is a little boy", claimed Dare. "They are just using him as a shield."
Asked whether he had talked to the boy on the phone the grandfather replied, "He does not like to be there."
Khadija, 24, also appeared in ISIS videos of the past, in which she spoke about her new lifestyle in Syria and was shown practicing shooting. She was one of the pioneers of this type of propaganda, and she is considered to be on the most effective in mobilizing Western women to the ranks of Islamic State.
Henry Dare said he talked with his daughter a few weeks ago "but I usually ignore her calls because it is shameful to our family and herself."
Shortly before her 18th birthday, Khadija, then known as Grace and a devout Catholic, came home and told her mother, "I am a Muslim now." In Syria, she met a Swedish ISIS fighter named Abu Bakr and married him.
In one of the clips, Khadija explained that she "could not find anyone in the UK willing to sacrifice his life in this world for the afterlife. I prayed to Allah and he decided that I should come to Syria and get married to Abu Bakr."
According to several reports, since the video was shot, Abu Bakr was killed in the fighting in Syria.