The case of the Austrian kidnap victim Natascha Kampusch has been unexpectedly reopened after revelations that police apparently botched the investigation into her abduction — and tried to cover up their mistakes.

The Austrian Interior Ministry has started an internal investigation while lawyers for Ms Kampusch explored the possibility of taking legal action against the authorities, which could result in damages claims of up to €1million (£750,000).

The case was officially declared solved more than a year ago, but a former leading police official broke his silence on how investigators neglected decisive evidence that would have led to the kidnapper and covered up their mistakes deliberately to avoid a scandal.

“It appears that, despite firm evidence, I had to wait a whole eight years until I managed to find my way to freedom with my own resources. I am both appalled and furious at how priorities are being set here,” Ms Kampusch, 19, said, adding that officials had tried to “sweep the matter under the carpet”.

The evidence was put forward by a police officer who had been working on the case one month after the abduction in 1998. The officer, who was not named, reported in detail on the kidnapper Wolfgang Priklopil, stating that his van, which was used in the abduction, matched one that was described by witnesses.

His report read: “The man is a loner and has got extreme difficulties in communicating and integrating with the environment. He seemingly lives in the house with his ageing mother and is said to have sexual inclinations towards children. He could also have weapons in his home.”

Senior investigators failed to act on the report which, it is believed, could have led to the release of Ms Kampusch and spared her the eight-year ordeal. Unrelated to the report, two officers questioned Priklopil over his van but dismissed him as a suspect, even though he was unable to provide an alibi for the day of the kidnapping.

Priklopil, 44, snatched Ms Kampusch, who was aged 10, from the street as she walked to school in March 1998, and kept her captive in a bunker beneath his house near Vienna until she escaped in August 2006. He committed suicide within hours of the escape by jumping in front of a train.

The scandal was revealed by Herwig Haidinger, former head of the Federal Criminal Police Office, who discovered the report soon after Ms Kampusch's escape. He claims to have been ordered by superiors, including the cabinet of the then Interior Minister, not to investigate his findings in order to avoid “creating a scandal involving the police before the upcoming elections”.

Ms Kampusch's lawyer, Gerald Ganzger, said that the revelations were shocking and announced the possibility of legal action against the state of Austria for public liability resulting in “eight years of suffering and loss of income”. “This mistake has possibly cost her eight years of her life. The consequences of it clearly resulted in a tragedy,” Mr Ganzger said.

He added that the disregarded report was factual and professional, and a “textbook example” of leads that fitted the profile of a likely perpetrator.

According to experts, if the allegations were proven in court, Ms Kampusch could claim up to €1 million in damages.

The Austrian Interior Ministry has established a special commission to investigate the allegations. The officer who filed the report, as well as other witnesses and officials, are expected to give evidence.

Meanwhile, prosecutors and the Internal Affairs department are investigating whether the ministry made illegal attempts to cover up police negligence.

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