Natascha was kidnapped on her way to school, aged ten, by pervert Wolfgang Priklopil and kept prisoner for 3,096 days before she finally freed herself.
The story of her ordeal was recently made into a film starring Irish actress Antonia Campbell-Hughes.
According to the official version of events Priklopil, 44, threw himself under the wheels of a train in Vienna as the police net closed in.
However, a dossier of material gathered by a senior police detective charged with investigating the case who later apparently committed suicide has now caused the case to be reopened.
Colonel Franz Kröll, 59, was a career policeman who was in charge of the Kampusch investigation and claimed to have discovered a significant lead when he was ordered to drop the case. However, he carried on investigating independently, but six months later he was dead in an apparent suicide.
That it was a suicide has been doubted by many after a bullet hole in the wall that was supposed to have been from the gun he used to kill himself turned out to be from a screw from a washing line.
In addition, there were traces of gunpowder from the shot on both of the dead man's hands – as if he had been trying to hold the gun in what would have been a typical defensive move. If he had simply shot himself with his right hand this would have meant the traces from the shot would have been only on one hand.
Prior to that there were many other indications that the death was not a suicide, including the fact that his brother insists that the handwriting on the farewell note is not his brother's. A handwriting expert who examined the dead man's signature claims that there was no way the two handwriting styles had been written by the same person.
The dead man's paperwork and private notes however had been given to the cop's brother Karl Kröll, and this is now the basis of the new investigation by prosecutors.
Karl Kröll believes that the investigation into Priklopil's death was not thorough enough, and that he may have been killed by someone before his body was hit by the train.
Karl said: "I met a senior police official who was one of my brother's colleagues at his funeral. I told him that there was more evidence, and then I got arrested and locked up. It is bizarre that despite so many people having questions in this case, the only one to end up being arrested was me."
Most suspicion has fallen on Priklopil's best friend, Ernst Holzapfel, who it is alleged was allowed into the kidnapper's house and was mysteriously permitted to remove computer equipment, according to one witness.
He also inherited all of the dead man's property, and seized his savings accounts after claiming that his former best friend had borrowed money from him.
An eyewitness to the original kidnapping, a schoolgirl who was not believed at the time by detectives, had claimed all along that there were two kidnappers.
After Natascha was rescued, it was revealed that everything else about the girl's description including the type of vehicle used was correct. With regards to the second person, Austrian officials claimed the schoolgirl had simply been mistaken.
Story courtesy of Central European News.