Natascha Kampusch was snatched on her way to school in 1998 and imprisoned in a cramped cell until she fled successfully in August 2006, aged 18. Her abductor, Wolfgang Priklopil, committed suicide hours after her escape.
Theories had circulated suggesting Priklopil had accomplices. But during a presentation of the latest - and final - findings in the case, senior prosecutors and other officials said they found no evidence that Priklopil had help carrying out his crime.
"The so-called 'multiple offender' theory ... can be excluded," Werner Pleischl, senior Vienna public prosecutor, told reporters at a news conference aimed at presenting the latest - and final - findings in the case.
"We are certain there was no accomplice," echoed Ernst Geiger, a senior criminal affairs official.
Prosecutor Thomas Muehlbacher said a former friend of the kidnapper said Priklopil had admitted the abduction to him shortly before his suicide. The man, identified only as Ernst H., said Priklopil told him he carried out the kidnapping because he felt he would never be able to find a wife.
There were no indications that Priklopil knew Kampusch or anyone in her surroundings, Muehlbacher added.
Geiger acknowledged that investigators made mistakes in their initial probe.
Among other things, police did not follow up on a 1998 tip that pointed to Priklopil.
"Did police make mistakes in the investigation?" Geiger said. "I answer that with a clear yes."
