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Woman kidnapped by doctor wakes up in his secret bunker

Isabel’s life was turned upside down when her date drugged her with strawberries
Image of Swedish kidnap victim Isabel Eriksson and her kidnapper, Swedish doctor Martin Trenneborg.Instagram
  • Isabel Eriksson went on a second date with doctor Martin Trenneborg
  • He fed her champagne and chocolate-covered strawberries laced with date rape drug Rohypnol
  • Isabel woke up locked in his secret bunker

When Isabel Eriksson opened up her email, one notification caught her eye. 

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As an escort for seven years, Isabel, then 30, often had requests from potential clients and this booking was promising. 

Martin Trenneborg, a 39-year-old finance worker, had booked a date with her in September 2015. 

After exchanging messages, Isabel, who charged $3900 a night, found the man ‘normal enough’ and agreed to meet him.

After working in the industry for so long, she knew how to take care of herself. 

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At their first meeting, Martin seemed intelligent and calm, so when he requested a second booking, Isabel agreed.

The evening started off innocently. Martin brought champagne and chocolate-covered strawberries and delighted in feeding Isabel the fruit. Then her world went black.

When she woke, she realised she was no longer in her apartment, but a different building entirely. The ceiling was tin, not plaster like in her home.

Next to her was Martin Trenneborg, sitting in a chair looking at her. Heart racing, Isabel tried to recall what had happened, when she spied a needle in her arm. 

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A picture of former Swedish escort Isabel Erikkson who was kidnapped by doctor Martin Trenneborg. She is blonde and looking side on at the camera.
Isabel Eriksson (Credit: Instagram)

Fear gripped her as Trenneborg confessed that he’d kidnapped her, detailing his plans to keep her as a ‘sex slave’ for years.

He’d drugged the berries with anti-anxiety drug Rohypnol which is often used in date rapes. Using a prosthetic face mask to obscure Isabel’s identity, he bundled her unconscious body into a wheelchair to get to his car. He then drove 563km from the city to his remote farm in a rural town. 

‘The door is built like a bank vault and you will never be able to open it,’ he warned. 

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‘You will stay here as my girlfriend to have sex two or three times a day, clean and cook.’

Eyes wide with panic, Isabel wasn’t going to sit around and wait for help. She had to escape.

Terrified, she ripped the cannula from her arm and tried to launch herself at her kidnapper, clawing at him with two nails she’d found.

Still feeling the effects of the sedation, her efforts were futile. 

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‘If you try that again I will fix you to the bed in chains, and only feed you crispbread,’ he threatened before leaving her alone.

‘If you try that again I will fix you to the bed in chains, and only feed you crispbread,’ he threatened.

In the bunker (Credit: Swedish Police)

Isabel took in the cold and dusty room, measuring around 60 square metres. The concrete-reinforced walls were thick and the bunker had a bedroom, toilet and a fitted kitchen. 

Isabel couldn’t work out if the dungeon was above or below ground. 

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Trenneborg, who was actually employed as a doctor, visited his hostage at around half past seven in the morning. 

He’d take her to the small covered courtyard, so she could go outside without any risk of being seen by neighbours. He’d then leave her alone in the bunker, returning at around 6pm after work.

One morning Trenneborg withdrew blood from Isabel and took vaginal samples, which he told her he’d test at a lab at work. 

He said he didn’t want her to have any STDs, as he planned to have unprotected sex with her. 

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Another day, Isabel couldn’t believe her luck when an unknown man appeared inside the room. 

‘I was kidnapped and I’m being held hostage,’ Isabel said, pleading for help.

Surely this man was the ticket to her freedom. But when Trenneborg removed his incredibly realistic mask, she realised it was him and she’d been duped.

Isabel wondered if she’d ever make it out alive.

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Rubber masks used by Swedish doctor Martin Trenneborg to kidnap his victim Isabel Eriksson
Masks used by Swedish doctor Martin Trenneborg (Credit: Swedish Police)

One night, Trenneborg changed tactics, and rather than leave her alone, he insisted they share a bed.

Despite having treated Isabel like a hostage, he was now acting like her boyfriend.

Isabel was confused, and scared, but she played along, hoping it would buy her time until she could hatch a plan to escape.

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After six days of hell, every moment living in fear, Isabel was shocked when her captor bundled her into his car and drove her to the city where they went to a police station. 

With news reports swirling of Isabel’s disappearance, Trenneborg had panicked. 

He told police that he and Isabel had tried to get into her flat, but because she had been reported missing, police had changed the locks.

Isabel had been given a bogus story to tell detectives – that she’d willingly left home to spend time with Trenneborg and was in no danger. But when police questioned her alone, she spilled on her horrific and traumatic ordeal. 

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Inspecting Trenneborg’s computer, police found a written contract saying a woman would serve as a sex slave and by co-operating, a year would be removed from her time in the bunker.

The hull of one of the strawberries Trenneborg drugged Isabel Eriksson with (Credit: Swedish Police)

Although Trenneborg was initially charged with rape, his trial in January 2016 ruled there was insufficient evidence to confirm that he had sexually attacked her. 

In February 2016, Swedish doctor Martin Trenneborg, then 38, was convicted in Stockholm District Court of kidnap and jailed for 10 years.

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A later appeal on the grounds Trenneborg suffered depression at the time, cut his prison sentence to eight years.

Isabel quit the escort industry, focusing instead on overcoming her life-changing ordeal. 

‘Every client I’d had before was fine and perfectly respectable – Trenneborg was my first and only bad experience,’ she told the Daily Mail in 2023. 

Last year Isabel, now 39, featured in a documentary called The Bunker, where she returned to the scene of the crime to work through what happened. 

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‘I hope that it can free me from all these horrible memories,’ she said.

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