We're close on identity of IS killer Jihadi John - MI5 chief
Britain's intelligence agency MI5 has said they are "getting warm" on the identity of the militant seen in Islamic State's (IS) beheading videos.
The foreign secretary Philip Hammond also condemned the continuing hostage situation involving British aid worker Alan Henning (47) after IS, also known as ISIL, sent an audio recording to his wife Barbara in which he pleads for his life.
Mr Hammond told American network CNN the investigation into the masked killer, dubbed Jihadi John and thought to be British, was closing the net.
Speaking to Situation Room host Wolf Blitzer at the United Nations summit in New York, he said: "MI5 are getting warm, we are working on all the leads. There's a big investigation and we are getting warm.
"We are narrowing down the field but I don't want to say any more at this stage."
Mr Henning, who appeared at the end of a video of the murder of British aid worker David Haines, was kidnapped last December in Syria by IS militants and Mrs Henning has again pleaded for them to release him.
The militant extremist group has previously released footage showing the killings of American journalists James Foley and Steven Sotloff as well as Mr Haines. The man known as Jihadi John is believed to appear in all three videos and seems to speak with a British accent.
Barbara Henning called for the militant group to "open their hearts and minds" and said she had been told that a Sharia court had found her husband innocent of being a spy.
"An audio file of Alan pleading for his life has just been received by me.
"I and people representing me continue to reach out to those holding Alan. Islamic State continue to ignore our pleas to open dialogue.
"I have seen Muslims across the globe question Islamic State over Alan's fate. The voices of the people have spoken out loud and clear. He was working with Muslims to help the most vulnerable within Syria. Nothing has changed. Please release Alan," she pleaded.