Police have received a number of pieces of information since announcing a £20,000 reward in the Damien Nettles case.
Officers said each piece of information must be assessed methodically and that their biggest challenge they still face is separating fact from fiction.
Superintendent Dave Powell, leading the investigation, said: "We have spoken previously about the large amount of rumour and misinformation that surrounds this case. We do not want to make hasty premature judgements about the significance of information received as a result of the reward offer or any other enquiries we make.”
Meanwhile the officer heading the case has apologised for the loss of CCTV footage which showed Damien's movements in Cowes High Street after he left Yorkie's fish and chip shop on November 2, 1996.
Superintendent Dave Powell added: "Damien's parents viewed this footage with police in 1996 and positively identified Damien on that CCTV camera at 12.02am on Sunday, November 3, 1996 walking to a bus stop and then back along the High Street eating his chips.
“This matter was included in a previous review of the case carried out by Hampshire Constabulary. This review confirmed that CCTV footage from Cowes High Street on the night of Damien’s disappearance was lost by the police.
“We 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. Experiences from our past are used to learn and improve, and detectives remain firmly focused on finding the ultimate answers to locate Damien, to provide answers for his family, and bring anyone responsible for a crime to justice," he added.
Police have also said speculation about the identities of suspects could jeopardise the case, and appealed to the public and media not to publish such speculation.
Superintendent Dave Powell said: "Eight people were arrested on suspicion of murder during 2011. They were questioned and investigated over the course of a year and released with no further action and no charges.
“We would again ask all media and members of the public not to publish speculation about the identities of previous or potential suspects. Such speculation is likely to jeopardise lines of enquiries to find Damien.
“We continue to keep an open mind, 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."
At the time of his disappearance, the description of Damien was:
- Six foot three inches tall
- slim build
- short brown hair, shaved at the back
- brown eyes
He was last seen wearing:
- A black fleece jacket
- Dark blue jeans
- Black boots
Anyone with information about the Damien Nettles case can contact Hampshire Constabulary by phoning 101 and asking for the Major Investigation Team at Fratton police station in Portsmouth or emailing email@example.com Mini-Com users can call 01962 875000. Information can be given anonymously by phoning the independent Crimestoppers charity on 0800 555 111.