The widow of British aid worker David Haines who was beheaded by 'Jihadi John' said the Islamic State militant must be caught alive.

Dragana Haines said the militant extremist, named yesterday as Mohammed Emwazi, who had been known by MI5 services since 2009, must be brought to justice and not be given 'an honourable death'.

"I hope he will be caught alive," she told the BBC.

"That's the only moral satisfaction for the families of all the people that he murdered, because if he gets killed in the action, to put it that way, it will be an honourable death for him and that is the last thing I would actually want for someone like him.

"I think he needs to be put to justice, but not in that way."

Emwazi, who is from West London and a former Westminster University graduate, is linked to videos of the beheadings of aid workers and journalists including Haines, Steven Sotloff, James Foley and Alan Henning. Other victims were Peter Kassig, Haruna Yukawa and Kenji Goto.

Haines's daughter, Bethany, warned families will only "feel closure and relief once there's a bullet between his eyes".

A statement released by the Sotloff family, said: "We want to sit in a courtroom, watch him sentenced and see him sent to a super-max prison."

Advocacy organisation Cage – former known as Cageprisoners – caused outrage at a press conference yesterday – depicting Emwazi as a 'kind and thoughtful' man and blamed security services for harassing him over his connection with Somali Islamist militant group al Shabaab. It was also revealed MI5 later tried to recruit him.

Amandla Thomas-Johnson, a Cage spokesman, said: "We have our views on foreign policy and domestic policy; it may be unpopular to the powers that be. We have been on the ground speaking to the people who have been through this. We're not offering excuses, we're offering an explanation."