A former member of the Islamic State today claimed he witnessed the British graduate dubbed Jihadi John behead a Japanese hostage . The man , named only as Saleh , said the masked militant who appears in several beheading videos was a senior figure in the extremist organisation responsible for murdering foreign captives . Jihadi John , who was recently unmasked as 26-year-old Londoner Mohammed Emwazi , was last seen in a video posted online which appeared to show Japanese hostage Kenji Goto lying dead . Saleh , who worked as a translator , also revealed that ISIS routinely subjected hostages to mock executions so that when their beheading did finally come they were not expecting to die . ISIS executioner Mohammed Emwazi who is known as Jihadi John ( seen , left , with Japanese hostage Kenji Goto ) was a senior figure tasked with murdering foreign captives , claims a defector known as Saleh ( right ) Face of a killer : Saleh , who worked as a translator , revealed that Emwazi ( above ) routinely subjected hostages to mock executions so that when their beheading did finally come they were not expecting to die . Speaking to told Sky News in broken English from Turkey after fleeing ISIS , Saleh said : 'When he killed Kenji Goto , I live showed this ( saw this ) but not near , from a little ( distance ) . 'The big boss was there with them . Turkish man say `` put this camera there , change place there '' but John ( was ) the big boss . 'All time , all time say to all `` fastly , fastly , fastly , we should finish '' . So respect him . Only he talks orders - others do . ' Saleh said the prisoners would be given Arabic names to make it appear like they were with friends and continually reassured that they would not be killed . He said : 'He would say to me `` say to them , no problem , only video , we do n't kill you , we want from your government [ to ] stop attacking Syria . `` We do n't have any problem with you ; you are only our visitors '' . ' Saleh said he explained to the hostages that they were safe , but always knew they would be killed . His comments explain why so many of the prisoners appear so calm in the executions videos right up to the point where the knife is placed against their throat . A still photo of Kenji Goto holding a picture of Jordanian pilot Mu'ath al-Kaseasbeh . ISIS defector Saleh revealed how hostages were given Arabic names to give them the impression they were among friends . After Mr Goto was killed , Saleh said three of four men put the body in the boot of a car and drive off , with Emwazi leaving in a different direction . Appearing with his face covered , the man added Jihadi John won respect for murdering foreign prisoners . He said : 'Maybe because he use the knife . I can not understand why he is so strong . 'One man can kill and all people will respect . A Syrian man anyone [ in ISIS ] can kill . But strangers [ foreigners ] , only John . ' And hostages were routinely subjected to mock executions , with their captors telling them they would not be killed as it was a show for the camera , according to Saleh . Murderer : Jihadi John seen ( in black mask ) leading the execution of a dozen prisoners . Emwazi was a senior figure in the extremist organisation responsible for murdering foreign captives , according to defector Saleh . Kuwait-born Emwazi had been pinpointed as a potential terrorist by the British authorities , but was nonetheless able to travel to Syria in 2013 and join a group responsible for the murder of several Western hostages . In e-mail exchanges with a journalist , the University of Westminster computer programming graduate said he considered suicide after coming face to face with what he suspected to be a British spy as he attempted to sell a laptop computer in 2010 . Jihadi John rose to notoriety after he first appeared in a video posted online last August , in which he appeared to kill American journalist James Foley . Dressed in black with a balaclava covering all but his eyes and the ridge of his nose , and a holster under his left arm , he reappeared in videos of the beheadings of US journalist Steven Sotloff , British aid workers David Haines and Alan Henning , and American aid worker Peter Kassig . He later featured in a video with Japanese hostages Haruna Yukawa and Kenji Goto , shortly before they were killed .
Defector : Steven Sotloff was responsible for killing foreign prisoners . Staged fake executions while reassuring them they would not be murdered . Captives were given Arabic names to lure them into false sense of security . Explains why hostages appear calm right to when knife is placed on throat .