ITV Until I Kill You's creator reveals utterly chilling detail about the real Delia Balmer

The creator behind has shared a stomach-churning revelation about Delia Balmer.

Set in 1991, the series follows London-based agency nurse Delia Balmer (), who initially believes she's found a true romantic connection with 'fellow free spirit' (Shaun Evans). After meeting a pub in Camden, north London, Delia believed she had found common ground with carpenter and casual labourer Sweeney, who shared her love of travelling. On the surface, Liverpool-born Sweeney appeared to be a loved-up boyfriend, regularly treating the then 40-year-old Delia to bunches of flowers.

– who would later inflict his rage onto her. In her 2017 book Living With a Serial Killer, which has helped inform the series, Delia, who now views his displays of affection as manipulative, recalled: "Subtle changes happened slowly. I should've known something was wrong but I am too soft and trusting. I'd never come across anything like it before."

Sweeney ended up moving into Delia's home and suspicions were later raised by his temper, his behaviour later became controlling and abusive. Living in terror, it took Delia years to ask Sweeney to leave - and he reacted with shocking cruelty. Although she'd first asked him to leave in December 1993 Sweeney continued to manipulate Delia, with his abusive behaviour escalating sharply in the spring of 1994. Over the course of several days, Sweeney held Delia captive in her own home, keeping her restrained to the bed, and threatening to mutilate her tongue if she screamed.

In 1994, Delia was tied to her bed for four days and also attacked with an axe during one of Sweeney's abuse filled rages. Show writer Nick Stevens has opened up about his bond with Delia, who he first met three years ago – admitting their first meeting went very badly. Speaking to , Stevens said: "Amazingly, Delia still sleeps in the bed Sweeney made for her and to which he tied her for four days. I can't be sure how she processes all this. But I'm certain she's in a better place than she was."

Although most show writers have some engagement with the real person behind the story, Stevens admits that he and his wife are in regular contact with Delia. He commented: "It's a regular thing now that my wife and I take Delia out to a Greek restaurant in London. She is a different person to the one I met two or three years ago. It seems to have been a positive for her. You might expect someone who has been through all that to be tearful with moments of gloomy introspection. But there's none of that."

During Delia's terrifying experience, Sweeney confessed to murdering his ex-girlfriend, model and photographer Melissa Halstead, whose remains were recovered from a Rotterdam canal in 1990. Remembering Sweeney's chilling words in her book, Delia wrote: "We had a room in Amsterdam. I went in. There were two Germans there with her. I killed them all. I didn't know what to do with the bodies. I sat with them for three days. On the third day, I cut them up, and I put them in bags and I threw them in the canal."

He later targeted and murdered mum-of-three Paula Fields in 2000, tossing her body into London's Regent's Canal. In 2001, he was finally caught and arrested, and given a nine-year custodial sentence against Delia. While serving time at Leicestershire's Gartree Prison for the attack on Delia, Sweeney was also questioned about Melissa and Paula, with officers suspecting a connection. Eventually, advances in DNA on top of Delia's testimony, helped authorities build a case against evil Sweeney, and put him away for good.

After being found guilty of killing both women, Sweeney was sentenced to life imprisonment in 2011 without the possibility of parole and remains incarcerated. Horrifyingly, as reported by the , it's believed Sweeney could have killed three other women who were reported missing between the years 1970 and 1990.

The brutal killer refused to leave his prison cell at Belmarsh prison as his sentence was handed down. Judge Mr Justice Saunders, sentencing him, told the court at the time: "These were terrible, wicked crimes. The heads of the victims having been removed, it is impossible to be certain how they were killed. The mutilation of the bodies is a serious aggravating feature of the murders."

The final episode of Until I Kill You airs tonight, November 6 at 9pm on ITV1.

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