THE brother-in-law of beheaded British hostage Alan Henning condemned his killers as “scum” last night and prayed they “get what’s coming to them”.

Colin Livesey spoke of his anger after the murder of the 47-year-old taxi driver at the hands of Islamic State killers who filmed it for a sick video message.

Mr Livesey, the brother of Mr Henning’s wife Barbara, said she was “devastated” by the murder of the “decent, caring human being”.

He questioned whether the Government did enough to help Mr Henning as it emerged the elite of Britain’s special forces and spies have been tasked with bringing the killers to justice.

Mr Livesey vented his anger at ministers, saying: “They could have done more when they knew about it months and months ago.”

He said his family had been left “devastated” and said he would always remember his brother-in-law, an aid worker in Syria, as a “kind, gentle man that made me laugh”.

He added: “There was just no need. For a person who went there to give aid, to help their kids, their people in Syria, and for them to do what they have done, there is just no sense in it at all. I just hope and pray they get what’s coming to them.

“There are no words in the dictionary to describe how I feel towards them, I’ve just got so much hatred for them.”

Last night the head of Interpol said IS should be renamed CM for Cowardly Murderers. Secretary General Ronald Noble said the beheading of Mr Henning was “testament to the depravity” of the organisation and showed it had no religious principles.

The murder of Alan Henning was absolutely appalling. It is senseless; it’s completely unforgivabl

Mr Cameron

David Cameron has ordered the SAS, SBS, MI5, MI6 and GCHQ to find the killers in the biggest terrorist manhunt mounted by the UK.

Worldwide revulsion over the Islamic State beheading of the father-of-two from Salford, Greater Manchester, by the masked executioner dubbed “Jihadi John” has increased the resolve of the PM to eliminate the extremists.

He received a briefing from military commanders at his Chequers retreat 10 hours after IS released its video of Mr Henning kneeling in orange prison fatigues and forced to make a prepared statement in which he blamed his death on Parliament for authorising RAF air strikes.

“Anyone in any doubt about this organisation can now see how truly repulsive it is and barbaric it is as an organisation. What we see with this organisation is that there is no level of depravity to which they will not sink.

“The fact that this was a kind, gentle, compassionate and caring man who had simply gone to help others, the fact they could murder him in the way they did shows what we are dealing with.

“We must do everything we can to defeat this organisation. We must take action against it and we must find those responsible. Everything we can do we will do but it’s going to take, this struggle, patience, hard work and resolve to defeat this organisation. But I know this country, we have that resolve.”