The mother of an Isle of Wight teenager who disappeared 16 years ago has renewed her plea police to investigate two potential burial sites.
Damien Nettles was last seen in West Cowes on 2 November 1996.
Valerie Nettles has passed on tip-offs, one from a clairvoyant, that Damien may be buried at sites around Gurnard or Parkhurst Forest on the island.
Detectives dismissed the sources of the information as "unreliable and inaccurate".
They said they remained "determined" to find Damien.
Supt Dave Powell said the information came from a seance and people with a criminal background. He insisted neither were credible enough to justify police resources being used in a search for human remains.
"We want the truth, facts and accurate information, we don't want rumour, gossip and speculation," he said.
Police said that since announcing a £20,000 reward on 4 October for information that would help them find Damien, officers had received 20 pieces of information.
The cash remains on offer until the beginning of April 2013.
Mrs Nettles, who now lives the US, said the 16th anniversary of his disappearance would be particularly difficult.
She said: "Sixteen years, this is my child - it just kind of marks that weird deadline where I had him for 16 years and now I've lost him for 16."
She believes Damien may have been killed over a cannabis debt.
"Maybe old loyalties got in the way in the past that perhaps are no longer an issue. People need to realise this is a one off opportunity.
"We just want to lay Damien to rest, give him back some dignity and put this ambiguous grieving to rest," she said.
Adverts appealing for information about Damien are being screened on Wightlink ferries from the anniversary week until the end of the reward period.
Supt Powell said: "Murder or a crime cannot be ruled out.
"But I stress again that speculation, gossip and the spreading of rumours won't help the police and the Nettles family find the answers we seek in this investigation.
"We are determined to solve this case with the help of the community.
"The information received over the past month is being assessed by detectives who are keeping an open mind about future lines of enquiry."
Eight people were arrested last year but released without charge.
The last remaining CCTV footage of Damien shows him at Yorkie's fish and chip shop in Cowes High Street at about 23:45 GMT.
Further CCTV evidence that showed Damien walking in the high street up to a bus stop after leaving Yorkie's was lost by police in the 1990s.
A spokesman said: "Police regret the loss of potential evidence in any investigation and have apologised to the Nettles family previously.
"This outcome was clearly disappointing and distressing for all involved."