Five years on, parents of missing Madeleine McCann cling to hope The parents of Madeleine McCann are more hopeful now, than ever before, that their daughter will be found. In an interview with British TV's Mary Nightingale, to mark the fifth anniversary of Madeleine's disappearance. ITN's Romilly Weeks reports. By Tazeen Ahmad, NBC News LONDON -- Year after year, a new photo of the British child Madeleine McCann has emerged. They are a collection of pictures that would have taken pride of place in any happy family home if they had been photos of a real child rather than the haunting computer-generated images of a girl who vanished into thin air five years ago. Madeleine's name has become synonymous with parental despair -- a heartbreaking story that has no end. Thursday marks the fifth anniversary of her disappearance while on holiday in Portugal. An international manhunt, numerous unsubstantiated sightings of her around the world, an unprecedented media campaign launched by her parents and a best-selling book followed, but so far, all of it has come to nothing. The child's parents Kate and Gerry McCann are, clearly, as distressed about her disappearance as they are determined to find her. In an interview with GMTV, a U.K. morning television show, they said that despite the passage of time they still had hope that Madeleine was alive. "We've always believed that and we're realistic; we don't know what's happened, but we know there's a very good chance that she could be alive," Kate McCann said. There's no evidence to the contrary [and] ... year after year, missing children that have been abducted are found alive. Teri Blythe / Met. Police - AFP - Getty Images A combination of images showing missing British girl Madeleine McCann at the age of three (left) and a computer-generated image released by police showing what police believe Madeleine could look like aged 9. "I think particularly the cases when they're younger children, it's often not horrendous circumstances," Gerry McCann added. A lot of the kids are taken as babies or toddlers; [they] have just been brought up as normal children and obviously with the older children, it's been a bit more unpleasant, but they are capable and adaptable and cope well. Other kids to continue search? Despite the enormous stress and scrutiny the couple have been under for 5 years, they are still very much together and their two other children, twins Sean and Amelie, are showing signs of their parents' dogged determination. "Even Sean said to me -- this is going back 18 months -- 'you know mummy if you haven't found Madeleine when we get older, me and Amelie will look for Madeleine,'" Kate McCann told GMTV. And I have absolutely no doubt about that, but I don't want them to have to be in the position where they're carrying around this kind of sadness and frustration or whatever ... to find Madeleine. We want to find her now," she added. TODAY's Matt Lauer talks with Kate and Gerry McCann about the ongoing search for their daughter Madeleine, the clue they may have missed and the strain this investigation has had on their relationship. What befell their family is the stuff of parental nightmares. Lucy Beresford is a psychotherapist who works in London and says couples whose children have been missing for long periods are forced to keep their lives on hold. It's a terrifying place to be; there is no proof one way or the other and a lot of speculation. The lack of clarity is exhausting," she said. At a press conference given by the McCanns Wednesday, it was clear to see the media obsession with this story is far from fading. And no one has worked harder to keep Madeleine's face and name in the spotlight than her mother and father. Missing girl Madeleine McCann may be 'still alive' It's hard to believe that half a decade has passed and yet she remains deeply imprinted in our minds. The credit goes to her parents who, despite their distress, have relentlessly pursued a high-profile and sophisticated campaign to find her. At its peak their "Madeleine Fund" raised more than $3 million, much of which has been spent on private detectives searching for her. Talking to the Pope, Oprah And with a book, regular front-page headlines, a meeting with the Pope and a television appearance on Oprah, the McCanns have managed a very astute media campaign to keep their daughter in the spotlight. Helping them with their media strategy is one of the smartest heads in the business, a tough former television reporter turned PR guru, Clarence Mitchell. They hired him early on and now he's a close friend of the family. He went from being a professionally dispassionate journalist to really caring about the people he is working for. British police have issued a new appeal for information on Madeleine McCann, the little girl who disappeared while vacationing with her family in Portugal five years ago. NBC's Tazeen Ahmad reports. At every media appearance made by the McCanns, he stands nearby ready to leap to their defense. Many say he is their secret weapon. And the timing last week of the British police's press conference could not have been better. A full week before the actual anniversary, it grabbed headlines all week. Andy Redwood, the police officer in charge of the British review of the investigation, told reporters that they were a quarter of the way through 100,000 documents and of these there were "195 investigative opportunities." He said they had taken "two positions" on Madeleine's disappearance. "One is that she is alive," he said, "and the other is that she is not, and in relation to the former and on the evidence we believe there is a possibility Madeleine is alive." Headlines sprung up in the hours and days afterward, focusing on the idea that the child could be alive and the general public sat up and took notice. Cop: Parents have to believe I asked Colin Sutton, a former chief inspector of London's Metropolitan Police, for his take on what may be going on behind the scenes. Could Madeleine really be alive after all this time? "Technically, you have to use these media opportunities to get help," he said, "you can't stress in an appeal that she may be dead or you are switching people off." Sutton, who was in the police's murder squad, then told me about some depressing statistics that all those involved in the police case review would be fully aware of. If a person is missing for more than 48 hours, there is a 90 percent chance that they won't be coming back. A lot of the team will be thinking that she simply isn't alive," he said. It's a fact, he added, that the McCanns also would have had to face and that while police officers would have been sensitive, they certainly wouldn't have shied from it as a distinct possibility. "They would have been told she is dead," Sutton said, "and they would have accepted that, but they, as her parents, also have to believe that she will be found one day." And that one day, the McCanns will be hoping, is soon. Their campaign to find her has not lost momentum over the past 5 years. It is certainly one of the most picture-friendly stories I have ever worked on. There are endless photos of this gorgeous little child, cute home video footage of her and her siblings. Her telegenic, middle-class professional parents wear their grief with dignity and have appeared on our television screens over and over again. But some are saying that this may be their last hope. And public opinion in Portugal is against the McCanns. Many still believe they were behind their daughter's disappearance. With Portuguese authorities as yet failing to take the cue to reopen the investigation, the British police's efforts can only go so far. Tantalizing dream of finding her So on this fifth anniversary all we really have is this new image of Madeleine that the family are hoping will finally lead to the closure they need. "Closure" is a word the British police used a lot last week. When pushed on what this means, they said they simply want the case solved. For the rest of us -- who have watched this story from afar, who want but are unable to help -- it's a poignant reminder that if she is still alive, she will be celebrating her ninth birthday next week. It is also a reminder that if she does reappear, it will be against all odds, making it an even more incredible story. But at the moment, that remains just a tantalizing dream for the McCanns. Kate McCann told GMTV she had imagined Madeleine being found alive, but tried not to. "You know what, I don't that often because it's almost like ... it's so good, it's so beautiful I guess, that I don't want to take myself there and for it not to be real," she said. I've had some dreams along the way, not recently and they're so tangible that it's incredibly painful because that's what we want every single day.