I will kill Jihadi brother myself, vows Konika Dhar if sibling confirmed as masked Briton in IS execution video
The sister of a British jihadi has said she will "kill him myself" if he is revealed as the masked militant in a new Islamic State video showing the murder of five hostages.
Konika Dhar, from north London, said she did not believe her brother was the man in the film, but she conceded the voice sounded "a bit like him".
It came as a small boy, who appeared in the footage, was named in reports as the son of a jihadi bride from south-east London.
The identities of those in the 10-minute clip, which is being closely examined by security services, have not been confirmed.
British Muslim convert Abu Rumaysah previously talked about the UK being brought under Sharia law by a conquering Islamic State (IS) army.
Born a Hindu called Siddhartha Dhar, he ran a business renting out bouncy castles in London before converting.
He was arrested in September 2014 when he was 31 with eight other men as part of an investigation into alleged support of the banned extremist group al-Muhajiroun.
But in a huge embarrassment for authorities he fled Britain with his family the following day after being released on bail, reportedly travelling to Paris and then Syria.
Ms Dhar said: "I don't think it is, personally, to be honest." She went on: "I examined the features - one eye is smaller than the other, my brother has symmetrical eyes.
"The eyebrows are bushy and this guy is taller, my brother is shorter and he has got broader shoulders, but he has got stooped shoulders, so I don't think it is.
"I think the voice sounds a bit like him, but it could be someone else, but he could have helped with a voiceover, but I have no idea."
She said she had not had contact with her brother in more than a year, saying she "doesn't even know who he is" any more.
Ms Dhar said: "If it is him, bloody hell, am I shocked? I am going to kill him myself. He is going to come back and I am going to kill him if he has done this.
"I can't believe it. This is just so shocking for me. I don't know what the authorities are doing to confirm the identity, but I need to know if it is."
Meanwhile, reports claimed a child seen at the end of the video dressed in military-style clothes and wearing a black headscarf with an IS logo on it was Isa Dare, the son of Grace 'Khadijah' Dare from south-east London.
The boy points into the distance and says in English: "We are going to go kill the kaffir (non-believers) over there."
Grace Dare was brought up as a Christian but converted to Islam and started using the first name Khadijah. She travelled to Syria in 2012 and married a Swedish man called Abu Bakr, who is believed to have been killed since.
The extremist, who according to the Daily Telegraph has a younger son as well as Isa, previously took to social media to say she wanted to be the first British woman to kill a British or American IS hostage.
Last year she was said to have posted a picture on Twitter of Isa with an AK-47 rifle.