British police have appealed for internet users worldwide to spread a new video aimed at pricking the conscience of the key witness who knows what happened to Madeleine McCann.
The one-minute film includes fresh images of how Madeleine might look now, including one with dark brown hair and tanned skin in case she has been living in north Africa.
The appeal, launched by the Child Exploitation and Online Protection (Ceop) centre, is targeted at a friend or relative of the person responsible for the little girl's disappearance.
Ceop head Jim Gamble said the clip's message, which has been translated into six other languages, had been crafted with the help of psychologists to persuade the witness to "do the right thing".
He 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. It is also highly probable that they, or someone close to them, is using the internet to search for any updates that may suggest the police are getting closer to discovering the truth."
Madeleine was nearly four when she went missing from her family's holiday apartment in Praia da Luz in Portugal on May 3 2007 while her parents dined with friends nearby. Despite a massive police investigation and huge publicity worldwide, she has not been found.
Kate McCann admitted there were still more things that could be done to look for her daughter. She told BBC Breakfast: "We haven't found Madeleine so we haven't done enough, which is why we're doing this appeal.
"We just keep going. And while we haven't found Madeleine, there are still things that obviously can and should be done."
Her husband Gerry added: "This isn't so much an appeal for information, it's really targeted at a small number of people. That's why we need it to be spread far and wide, and for those people to be exposed to this message as many times as possible."
Mr McCann told the programme the couple's four-year-old twins, Sean and Amelie, talked about Madeleine constantly. Urging parents to spread the Ceop video, he said: "If you've got children please follow this link and try and make us a happy family again - a happier family, because the twins are brilliant."