British police have released new age-enhanced pictures of Madeleine McCann as part of a fresh appeal for information.
The images were published in an online video which officers want Internet users to spread worldwide.
They hope the video will prick the conscience of "someone close" to Madeleine's abductor.
Investigators want a friend, colleague or relative of the culprit to finally reveal the secret they have kept since Madeleine, who was four years old, vanished from her bed in Praia da Luz, Portugal, in May 2007.
The appeal comes in a 60-second film which can be viewed on the Web site of the Child Exploitation and Online Protection Center (Ceop).
The simple film is available in seven languages and shows two images of Madeleine based on how she might look today, aged six.
One picture shows her with a deep suntan she might have developed if she is living in southern Europe or North Africa.
The initiative follows the McCann family's concern that little was being done officially to find their daughter.
The Portuguese police shelved their investigation last summer after clearing Madeleine's parents Kate and Gerry of any suspicion and failing to develop any clues to the mystery.
Ceop's head Jim Gamble said: "The person we are looking to reach is likely to be a partner, family member, friend or colleague of the person or people who were involved in Madeleine's disappearance.
"If you haven't divulged your secret because of love, loyalty or fear, be assured that it is never too late to reveal the information to your local police."
He added: "If you are a parent or carer, a student or member of the public who is a social networker, blogger or e-mailer, or if you run any type of online environment, big or small, please look at the film today, link to it, share it with your friends and post it in the online communities you occupy."
Interpol is backing the appeal and any information will be passed to the Portuguese authorities, who have said they would renew their investigation if fresh evidence emerged.
McCann spokesman Clarence Mitchell said: "Kate and Gerry believe this appeal will give fresh impetus to the search for their daughter."Click here to read more on this story from Sky News.