Previously unissued picture dated 11/9/2011 of Abu Rumaysah (left), formerly known as Siddhartha Dhar, whose sister has said that she will "kill him myself" if he is revealed as the masked militant in the footage showing the murder of five hostages.

Did my taunt push the new ‘Jihadi John’ to join Isis?

I offered to get Abu Rumaysah a one-way ticket to Syria only weeks before he fled

Even if Abu Rumaysah does turn out to be the new ‘Jihadi John’, shown on video this week presiding over the murder of five innocent men, I’m not sorry I encouraged him to go to Syria and join Isis.

The last time I saw the 32-year-old Briton (born to a UK Hindu family as Siddhartha Dhar) was at a BBC studio in London. He was one of a group of people who had been central to the extremist group al-Muhajiroun and its offshoots for years.