Freed hostages were able to give British police vital information that identified three of the Islamic State kidnap gang that had held and tortured them in Syria, it has been revealed. Scotland Yard has disclosed the breakthroughs that allowed it to identify three of the jihadis known as “the Beatles” and bring two of them to trial in the US. The hostages’ information helped police identify the men on a march with a group linked to the radical group al-Muhajiroun, together with the use of voice recognition software. Mohammed Emwazi, known as Jihadi John, first featured in a video released by IS in 2014 showing a masked man with a British accent shooting a prisoner. Police were able to locate tapes of police interviews with Emwazi in 2012, when he was questioned about a series of bicycle thefts, and compare that with his voice in the hostage videos. An expert forensic voice analyst concluded there was a “very strong likelihood” the person in the video was Emwazi. Officers then started to narrow down the pool of other potential members of the group, ultimately leading them to identify Alexanda Kotey and El Shafee Elsheikh, both from west London. Richard Smith, the head of Scotland Yard’s counter-terrorism command (SO15), said police followed a “trail of very small breadcrumbs” and building the case was “like putting together very small pieces of a jigsaw”. One piece of information emerged from the hostages they spoke to, which was “fairly unremarkable” to the hostage but proved very significant to police. It was the recollection of a conversation where one of the captors mentioned that he had been arrested at an English Defence League march in London. Based on that snippet of conversation, the investigation team was able to go back and identify a particular EDL march that took place in London on 11 September 2011. The march was a counter-demonstration against a march by Muslims Against Crusades to mark the 10th anniversary of the September 11 attacks, which began at the US embassy in Grosvenor Square. There were a number of flashpoints around central London and at about 6pm police were called to the Tyburn pub in Marble Arch, where a stabbing had taken place and a number of men were arrested on suspicion of involvement. Records showed that two of those arrested were Kotey and Elsheikh. “Both of the men ultimately were released without charge for that offence, but the information was invaluable in helping us to zero in on them as being the men the hostages had described to us,” Smith said. The Metropolitan police’s SO15 team took the opportunity to review data from Kotey and Elsheikh’s phones, which had been seized at the time of the arrest, and they showed various messages between them. They also found Elsheikh’s number saved on Emwazi’s phone, which had been downloaded when he was questioned over bike thefts. Another crucial piece of evidence linking Elsheikh directly to terrorist activity in Syria came as a result of officers taking a fresh look at evidence in an unrelated case. In 2014, Elsheikh’s brother, Khalid, was arrested by Operation Trident, the Met’s anti-gangs unit, and a handgun found at his address. His mobile phone was seized and found to contain disturbing images. That prompted the unit to contact SO15, which undertook a fuller examination. Police discovered a number of Telegram messages between Elsheikh and his brother, showing that Elsheikh was in Syria. One of the messages showed Elsheikh in combat clothing and holding a firearm. Another showed a graphic picture of decapitated heads with commentary from Elsheikh. After Kotey and Elsheikh’s detention in Syria, officers re-analysed the data using digital interrogation software – which had improved in the intervening years – and further material was discovered. A voice message was also identified from someone they believed was Elsheikh, which had been sent to his brother. After finding that voice message, they located a police interview tape with Elsheikh from 2009 and voice experts were able to compare the two recordings and conclude there was a “very strong likelihood” that Elsheikh was the person in the voice note. Last year, British police received authorisation from the attorney general for 139 charges against Kotey and Elsheikh, including kidnap and murder, but they were already in the US. The pair were stripped of their British citizenship after their capture by the western-backed Syrian Democratic Forces in 2018 and sent to the US for prosecution. Elsheikh, 33, from White City, faces sentencing on Friday. Kotey, 38, from Shepherd’s Bush, west London, was jailed for life in Virginia in April, after admitting kidnap, conspiracy to murder and providing material support for terrorism. The IS group, nicknamed the Beatles by their hostages because of their British accents, were responsible for the kidnap and holding of more than 20 westerners, and the killing of at least seven of them, including Britons David Haines and Alan Henning. Emwazi from Queen’s Park, west London, was known as “John”. He was killed at the age of 27 in a US drone attack on 12 November 2015. Elsheikh and Kotey were known as “Ringo” and “George”.