'I was imprisoned in a bunker by "Sweden's Josef Fritzl" and feared for my life'

A new TV documentary explores the warped rampage of Dr Martin Trenneborg, who gave the woman strawberries laced with the date rape drug Rohypnol, jurors were told

A woman who was kidnapped, drugged and locked in a bunker for six days by a man dubbed Sweden's Josef Fritzl feared she would die.

Isabel Eriksson, an alias used to protect her real identity, was targeted by Dr Martin Trenneborg, who gave her strawberries laced with the date rape drug Rohypnol, as part of his twisted plot.

He then drove her 350 miles from her Stockholm flat to a remote farm in southern Sweden where he planned to keep her as a sex slave. Speaking in court, Isabel said Trenneborg told her the door was built like a "bank vault" and she would "never be able to open it".

But the woman somehow survived the ordeal and was able to report Trenneborg to police. He was jailed for eight years after a jury found him guilty of kidnap. He was initially charged with rape, the trial ruled there was insufficient evidence to confirm that he had sexually attacked Isabel, whose case now features in a new documentary.

Isabel, now 47, recalls waking up inside a soundproof cell with a cannula in her arm. The documentary, called The Bunker is on streaming platform Viaplay and explores how Trenneborg managed to build the 60sqm military fortification himself - over a five-year period.

Then, in 2015, after kidnapping Isabel in Stockholm and driving her the 350 miles south, he thrust her into the chamber. Speaking in court in 2016, Isabel revealed Trenneborg made clear his intention was to keep her locked up "as a girlfriend", to "have sex two or three times a day, clean and cook".

She added: "He would come in at around half past seven in the morning, and then he would take me out in the courtyard he built." Isabel was working as an escort at the time, and Trenneborg, the court heard, wanted to have unprotected sex with her in the bunker.

But news of the woman's disappearance made the press and Trenneborg, then a freelance physician, panicked. The creep drove her to Stockholm where they walked into a city police station, and Isabel was able to report Trenneborg.

The nature of his crime coupled with the underground bunker where he kept Isabel, earned him the nickname of the "Josef Fritzl of Scandinavia". Austrian Fritzl was jailed in 2009 for rape and murder after keeping his own daughter, Elizabeth, locked in a cellar under his home for 24 years.

Isabel revealed in a 2017 interview how she woke to see a "tin roof and a man sitting on a chair next to me, just looking at me". She added: "I remember that he fed me strawberries. That I do remember. It is very hard to talk about. But after that I fell asleep everything was completely black. I 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 has kidnapped me and will have me locked up for a few years."