Police are now treating the disappearance of Nelson man Leo Lipp-Neighbours more than three years ago as suspicious.
They say information received from the public has led them to the conclusion that the 19-year-old's disappearance in 2010 may not be an accident.
Detective Sergeant Mark Kaveney would not say what that new information was, but said police wanted to ''shake the tree'' to shed further light on the case.
He said a dedicated investigation team had spent the last 10 months closely reviewing all aspects of teenager's disappearance and the searches completed for him.
Lipp-Neighbours, who was studying engineering at Canterbury University, was last seen in Nelson on Sunday January 24, 2010.
He disappeared from his Washington Valley flat at 4am. He had been drinking with friends at a Nelson club earlier in the evening. Before driving off into the darkness he told a friend he was going to be at one with nature.
A painstaking and extensive search of roads and roadsides in the top of the south uncovered no sign of him or his car.
Neither he nor his distinctive orange Toyota Corolla Station Wagon had been seen since.
Police were continuing to receive a constant trickle of information from the public and that had built a picture ''that led the investigation team to the conclusion that the disappearance now appears suspicious," Kaveney said.
''The wide range of information we have received leaves me considering the fact that Leo's disappearance is the result of another person's actions,'' he said.
''We are speaking with a large number of people and we believe there are other people in the Nelson community who know exactly what has happened.
''It is time now for those people to come forward, tell us what they know, and enable this matter to be brought to a conclusion.''
Kaveney said police had remained in contact with Lipp-Neighbours's family since his disappearance and he would dearly like to get them some answers and some closure.
''I believe that we are now looking for someone who has committed a serious crime against this young man. That person must be held to account.''
Crimestoppers offered a $50,000 reward for information leading to the location of Lipp-Neighbours and his vehicle. That reward is still in place.
Crimestoppers would determine the amount of the reward to be paid, and would, if necessary, apportion payment where there was more than one claimant.
Anyone with information that may assist this investigation can call Nelson Police, 546 3840. Anonymous information can be given by calling Crimestoppers on 0800 555 111.
- © Fairfax NZ News
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