A mother whose teenage daughter was stabbed to death by her friend's boyfriend has spoken of her heartbreak over the brutal murder. Julie Warren-Sykes' daughter Samantha, from Wakefield, West Yorkshire, was just 18 when her life was brutally cut short by Ahmad Otak, then 21, an Afghan asylum seeker who was jealous of her close friendship with his ex-girlfriend Elisa Frank. Determined to punish Elisa, he murdered her own sister in front of her - and in a horrifying twist, forced her to lure her Samantha to her death in March 2012. Scroll down for video . Julie Warren-Sykes' daughter Samantha was just 18 when her life was brutally cut short . Elisa's best friend Samantha Sykes (pictured), 18, was also killed by Otak, who slit her throat and stabbed her . Samantha and Elisa had been friends since they were eight years old. In a sickening act, Otak made Elisa watch as her killed her  sister Kim, 17, and best friend. Now survivor Elisa and Samantha's mother Julie have shared their experiences of that terrible day in TV show Britain's Darkest Taboos. Elisa, now 21, had been in a relationship with Otak after meeting him at a foster home as a teenager but Julie said her daughter had concerns about her friend's new boyfriend. 'She told me that she was concerned about Elisa's relationship with Ahmad Otak. She felt there was something wrong with the relationship, and she said that he gave her a bad feeling,' Julie said. Otak had become increasingly controlling of Elisa and tried to cut her off from her friend and younger sister. Elisa's sister Kim Frank (left) was stabbed 15 times by Ahmad Otak who then licked her blood off his knife . He threatened Elisa with violence and said he would harm her family and friends if she left him. But with the support of Kim and Samantha, she eventually plucked up the courage to end their relationship. She could not fathom that Otak would be carry through with his violent threats in the most horrific way. He asked Elisa to meet him at Kim's flat in Wakefield so he could collect some things from her. But when she arrived, he launched a ferocious attack on her sister as Elisa looked on helplessly. She recalled: 'All I can remember now is Kim fell on to me and I got pushed on to the bed a bit. Then I just turned round, and as soon as I turned round I saw the knife. 'Hearing Kim screaming, really horrific screams, like something that you can't really describe unless you have heard something like that. 'He was like, calling her a stupid b**** and stuff like that while he were stabbing her.' Elisa said Otak showed no remorse and seemed to gloat in the murder. 'He stood up, and licked the blood off the knife, and he spat down at her body,' she said. Survivor: Elisa Frank was the only survivor of the 2012 attack that led to the death of her sister . Then he made Elisa call Samantha and ask her to come to the flat. Terrified Elisa complied but hoped her friend - who had career aspirations as a model - would realise something was wrong and wouldn't go. 'I were hoping that she’d be able to pick something up from my voice, and then maybe phone the police,' Elisa said. But Samantha was a loyal friend to Elisa and worried something was wrong with her, she rushed to her aid. As soon as she arrived at the flat, she was stabbed to death by Otak. By then he had tied Elisa up with cable ties so she had no way of helping her friend. 'He seemed like he'd enjoyed it. Very calm, no emotion at all after he'd done it either, just none,' Elisa said of the murder. Meanwhile, Julie said she had a bad feeling something had happened to her daughter, who had left her a note saying she had gone to see Elisa. 'When I saw the note I had a bad feeling. It's a mother's instinct,' she said. But she admitted nothing could have prepared her for the news that her daughter had been brutally stabbed to death. The truth came out hours later after Elisa finally escaped Otak clutches as he tried to kidnap her by taking her to Dover to flee the country. Much missed: Elisa still has nightmares about the night Kim (pictured right) and Sam (left) were killed . She managed to get away and call the police and Otak was arrested and the bodies of his two young victims discovered in Kim's flat. Julie recalls hearing the terrible news after hours of anguish worrying about her missing daughter: 'Samantha was missing for a number of hours through that night, and I just kept thinking, "She’s dead." 'It’s not something that you can actually explain to anybody, it was just as if part of me had gone. It was an horrendous experience, the anxiety, feeling sick, just not really knowing what to do with yourself. You know, it's a mother’s worst nightmare. It was like torture. 'When the police came and told me what had happened, I think I just went into some kind of a shock, where everything seemed surreal. 'The worst thing in the world was always, for me, when somebody loses a child, and it was the one thing that I asked, "if there’s a God, don’t ever let that happen to me, don’t ever let that happen to me." Of course, it has happened to me.' Otak was tried at Leeds Crown Court after pleading guilty to the two murders but both Elisa and Julie were disgusted to see he showed no remorse for what he had done. 'To hear the detail of the injuries that both these young people suffered, is devastating. You just think, what is he thinking while he's sat there? Because he never showed any emotion whatsoever,' Julie said. Evil: Afghan asylum seeker Ahmad Otak attempted to flee to France but was foiled by a brave fellow refugee . Otak was sentenced to life in prison, with a minimum of 33 years and 124 days. Julie said of the sentencing: 'When he was sentenced you have a kind of feeling of euphoria, because you think, you know, that’s it, it’s done, he’s been sentenced, he’s got a long sentence. 'But that soon goes, and so, within a couple of days, actually I felt probably worse than I’d felt for a significant period of time. I just fell to pieces. I'm still grieving for Samantha, as are many other people, and you learn to live with what's happened.' Elisa says despite the lengthy sentence, she will never get over the death of her sister and best friend. She has turned to writing to help her deal with the events she witnessed and has written a book about her experiences called The Borderline Diaries. She said: 'Since I've started writing I've been feeling a lot better, and I've noticed that bits of my past and things that I haven’t been able to process so much, come out in my writing, and then I always feel a bit like I've had a weight taken off my shoulders afterwards.' Julie added that she wishes Elisa well and doesn't feel bitter about her part in her daughter's death. Aftermath: Police outside Elisa's Wakefield flat following the double murders . Traumatised: Elisa still has nightmares about the day her sister and best friend were murdered . 'She has an opportunity now that I hope she’ll grasp, and move forward with her life, and do something wonderful,' she said. She added: 'One of the real positive actions that we’ve taken as a family since Samantha’s death is to establish the Samantha Sykes Foundation Trust, whose purpose is to work with not-for-profit organisations who support and help victims of child sexual exploitation, or children and young people who are considered to be at risk of child sexual exploitation. 'We've been overwhelmed by some of the community support, and the generosity of local people has restored some of our faith in human kindness.' To learn more about Samantha Sykes Foundation Trust visit samanthasykesfoundation.com . Britain's Darkest Taboos continues on Sunday nights at 9pm only on CI and is repeated on Wednesday’s at 9pm .
Elisa Frank's sister and best friend were murdered by Ahmad Otak . Otak stabbed Kimberley, 17, 15 times and spat on her body . He forced her to lure Samantha Sykes, 18, and then murdered her . Sam's mother Julie Warren-Sykes speaks for first time since it happened . Shares her experience in TV show Britain's Darkest Taboos .