Natascha Kampusch was kidnapped and imprisoned for more than eight years in Austria (Reuters)
Natascha Kampusch was kidnapped and imprisoned for more than eight years in Austria (Reuters)

The investigation into the kidnapping of Austrian schoolgirl Natascha Kampusch looks set to reopen following claims the police officer who led the investigation was murdered rather than committed suicide.

Kampusch was just 10 years old when she was abducted in Vienna in 1998 by Wolfgang Priklopil as she walked to school.

Priklopil kept her captive for more than eight years in a specially built sound-proof cellar in the suburbs of the city. She eventually managed to escape in 2006. Her kidnapper was found dead on the same day in an apparent suicide after stepping out in front of a moving train just outside the Austrian capital.

Evidence has suggested that Priklopil may have had an accomplice which was covered up by police and the officer who "knew too much" killed as a result.

Six months after Kampusch escaped from captivity in 2010, cnl Franz Kroll of Vienna Police was found dead at his home from a gunshot wound to the head. Police ruled his death to be a suicide.

The brother of the detective, Karl Kroll, never accepted the suicide verdict and enlisted the help of to forensic expert Peter Leinzinger to help reexamine the case.

Cnl Kroll's brother says the detective was under pressure to present an alternative version of events to what happened to prosecutors.

The Independent claims Kroll told colleagues shortly before he was due to present his findings: "I am not going to go in there and lie to everyone's face".

He was found dead at his home outside his flat in the Austrian town of Graz six months later.

An undated police handout shows the passport photo of Wolfgang Priklopi (Reuters)
An undated police handout shows the passport photo of Wolfgang Priklopil (Reuters)

Now evidence from Leinzinger, a director of forensic medicine at Graz University of Medicine, has disputed the official findings into Kroll's death.

The evidence given by Leinzinger includes suggestions Kroll was killed by a right-to-left head shot, and not the left-to-right shot as recorded in the investigation. This would contradict the body position Kroll was found in, suggesting the corpse was moved after death.

Furthermore, police originally said the bullet that killed Kroll had "bounced off the wall". However, Leinzinger said that the hole left behind as evidence of this was in fact a hole "drilled to support a washing line".

Karl Kroll also says the suicide note left by his brother does not even have the same handwriting as the detective.

"My brother was killed because he knew too much," said Karl Kroll. "The scene [of his death] was constructed; it's just illogical.

"Professor Leinzinger's report will now form the basis of a parliamentary inquiry. This case must be finally resolved."

Claims that Priklopil had an accomplice in the kidnapping are also under investigation by a separate investigation into the Kampusch affair led by Johann Rzeszut, a former president of Vienna's Supreme Court.

He claims to have found several pieces of crucial evidence which police ignored in the original investigation, including an eyewitness statement from the only person believed to have seen Kampusch's kidnapping.

The 12-year-old girl, known as, Ischtar A, said she told police on several occasions she saw a man sitting in the driving seat of the van Priklopil used to snatch the girl off the street.

The witness, now aged 24, has since testified under oath that police told her not to mention the existence of a second man during their inquiry.

Kampusch has always denied someone other than Priklopil was involved in her kidnap.