‘Swedish Josef Fritzl’ drugged and kidnapped woman for six days keeping her in bunker as ‘sex slave’

A man, dubbed ‘Sweden’s Josef Fritzl’, kidnapped, drugged and locked up a woman before telling her she would be a sex slave for years.

In a new documentary, Isabel Eriksson has revealed the traumatic nature of her experience when she woke up imprisoned in a concrete vault and spent six days thinking she might spend the rest of her life there.

The mini-series ‘The Bunker’ details how Dr Martin Trenneborg fed Eriksson strawberries laced with Rohypnol in her Stockholm flat, before bundling her unconscious body into his car and driving 350 miles to his remote farm in 2015.

Isabel woke up and “saw a tin roof and a man sitting on a chair next to me and just looking at me. And I saw that I had a needle in my arm which I hurriedly pulled off. Then he said that he had kidnapped me and would have me locked up for a few years”, she said in a 2017 interview.

Trenneborg, who was a freelance physician, began designing his prison in the remote reaches of Southern Sweden 2010, replete with soundproofed 12.5 inch thick concrete-enforced walls.

When it was finished 5 years later, he paid £2,000 to spend the night with Eriksson, who then was working as a high-end escort, sedated her and transported her to his lair.

Speaking in court in 2016, Eriksson related how Trenneborg informed her the door to the vault was build like a “bank vault” which she would “never be able to open”.

“Then he asked me if I had any wishes, whether he should expand the bunker because I would be living here for many years”.

He intended, she said, to use her “as a girlfriend”, to “have sex two or three times a day, clean and cook”, and took blood vaginal samples from her to test for STDs so he could have unprotected sex with her.

Following news reports of Isabel’s disappearance Trenneborg panicked and escorted her to a Stockholm police station, telling her to give officers a cover story that she was safe.

But detectives became suspicious and questioned her alone so she could reveal her terrifying ordeal.

Trenneborg’s sick bunker plot has earnt him the nickname ‘The Josef Fritzl of Scandinavia’, due to what could have happened if he had managed to fulfil his designs.

Josef Fritzl carried out one of the grossest degradations of humanity over 24 years when he locked his 18-year-old daughter Elisabeth in his basement in 1984.

Until her escape in 2008, Fritzl would rape her on a daily basis, fathering seven children, three of whom were imprisoned in her basement with her, the other three being brought up as foundlings by his wife who he still lived with.

Fritzl had lured her into the cell after she’d run away from home that year, saying that he needed help carrying a door- the door that was the final piece of her prison.

She was allowed a TV, radio and video player, and In 1992 he permitted Elisabeth to enlarge her cell, by having her and her children spend years digging out soil with their hands.

Fritzl was sentenced to life in prison in 2009, after making a statement that his actions were inspired by the emphasis on discipline during the Nazi annexation of Austria, which began when he was two years old.

Isabel’s captor Trenneborg was jailed in 2016 for eight years for the kidnapping, although he was not charged with rape.

The court was shown a ‘sex contract’ he had drafted which required Isabel to provide him with a “GFE” or “girlfriend experience” which included shaving her body hair and kissing him, in order to reduce the amount of time she’d have to stay in the bunker.

Isabel has since written a book ‘You Are Mine’, and launched an OnlyFans page as part of her recovery, where she says she posts ‘artful’ and ‘tasteful’ pictures of herself.

Of Trenneborg, she says: “He was very convincing, and he seemed normal enough, but he was the complete opposite. Every client I’d had before was fine and perfectly respectable – Trenneborg was my first and only bad experience.”