Scotland Yard launches 'last chance' investigation into disappearance of Madeleine McCann as detectives identify 38 suspects Police are convinced the three-year-old was abducted by a stranger They have uncovered no evidence to suggest she has been murdered Launching a new investigation, officers say 12 of suspects are from UK Parents Gerry and Kate McCann along with their travelling friends known as the 'Tapas Nine' are not suspects The decision to launch a full criminal inquiry on foreign soil is with few precedents in the history of British policing Suspects include Urs Hans von Aesch who abducted and killed five-year-old Ylenia Lenhard less than three months after Madeleine was taken Von Aesch took his own life after killing his victim who looked like Madeleine By Chris Greenwood Scotland Yard has launched a 'last chance' investigation into the disappearance of Madeleine McCann Scotland Yard launched a "last chance" investigation into the disappearance of Madeleine McCann today. Detectives have identified 38 suspects, including several notorious paedophiles, from five countries including Britain and Portugal. They are convinced the three-year-old was abducted by a stranger and have uncovered no evidence that she has been murdered. As police unveiled the dramatic development and pledged to trace and question the list of suspects, they revealed: The little girl's parents Gerry and Kate, and travelling friends - known as the "Tapas Nine" - are not suspects. Detectives are trawling through more than 30,500 documents recovered from the Portuguese authorities, private investigators and other forces. More than 3,800 fresh lines of inquiry have been created by an exhaustive review of the chaotic aftermath of her disappearance. Any British suspect could be tried at the Old Bailey for the crime in Praia da Luz almost six years ago. Scotland Yard detectives said their two-year £5million review has created a "unique picture" of what took place at the holiday resort in August 2007. They are now launching a full international criminal probe in a bid to finally bring Madeleine's abductor to justice. Senior officers said compiling thousands of documents and witness accounts gave them a fresh insight into what may have taken place. They have already re-interviewed several witnesses, believed to be British holidaymakers, about what they know. Hope: Parents Kate and Gerry McCann have been told they are not suspects in the investigation The Ocean Club Resort in Praia Da Luz where the McCann family were staying when Madeleine went missing The Met will now reach out to judicial authorities in four countries, including Portugal, to help them track suspects. The decision to launch a full criminal inquiry on foreign soil is with few precedents in the history of British policing. Madeleine McCann disappeared from her family's holiday apartment in 2007 It carries huge risks as officers negotiate the complex tangle of international laws and procedures required to pursue those they believe are responsible. Det Chief Insp Andy Redwood, who is leading the inquiry, said: "The review has given us new thinking, new theories, new evidence and new witnesses. We, and the Portuguese authorities, remain completely committed to finding out what happened to Madeleine, and everything we do is utterly focused on her best interests. We continue to believe that there is a possibility that Madeleine is alive. It is a positive step in our hunt for Madeleine that our understanding of the evidence has enable us to shift this from a review to investigation. We have identified 38 persons of interest from a number of European countries. Twelve of those people are UK nationals who we believe were in Portugal at the time Madeleine disappeared. Our working relationship with the Portuguese police is positive and now that we have moved to investigation we are requesting further specific assistance through normal judicial routes. We remain in close contact with Kate and Gerry McCann and they are updated on our current position. The British investigation, known as Operation Grange, will continue to be funded by the Home Office. Officers met with Home Secretary Theresa May several weeks ago to brief her on the latest dramatic developments. Appeal: Kate and Gerry McCann hold a photo of their daughter which shows what she may look like now An image released showing what Madeleine McCann may have looked like in 2012 (left) and picture in her Everton football shirt before she was snatched (right) Never given up: Kate and Gerry McCann walk in Praia da Luz in 2007 where their daughter was abducted They are grappling with a huge haul of material from the Portuguese investigation and private investigators from seven firms employed by the McCanns. Leicestershire Police, which co-ordinated a deluge of tip-offs from around the world, has also passed on all the information it holds. Detectives said translating the material has created a "particular challenge" as has decoding other systems of judicial investigation. They have been ruthlessly prioritising material that could lead to the person or people responsible for abducting Madeleine. Investigators refused to discuss details of forensic evidence, but said they have no information to suggest the little girl has been murdered. Scotland Yard are launching a full international criminal probe in a bid to find Madeleine's abductor Detectives who have launched an international investigation are convinced the three-year-old was abducted by a stranger and have uncovered no evidence that she has been murdered Kate McCann has never given up hope that her daughter could still be alive One officer said: "In the absence of any clear evidence to the contrary we maintain our belief that Madeleine may still be alive." Officers from the Met have travelled to Portugal 16 times to share the findings of their review with the Policia Judiciaria and prosecutors. They said the review of the evidence is between half and two-thirds complete and will continue alongside the criminal inquiry. The officer added: "We are satisfied that our review has now progressed to a position where we have identified 38 persons of interest. These individuals are from a number of European countries and we are now at an advanced stage of dialogue with each country. Portuguese police, pictured at the apartment in Praia da Luz, accused Madeleine's parents of being behind the child's disappearance The beach at Praia de Luz in Portugal where Madeleine McCann went missing The Portuguese authorities have refused to reopen their inquiry into the disappearance of Madeleine McCann from The Ocean Club in Praia da Luz Over the coming months we will be conducting assertive inquiries, with the assistance of host countries to establish more information about the individuals concerned and any potential involvement. Twelve of the persons of interest are UK nationals who we believe were in Portugal at the time Madeleine went missing. Detectives have formally requested that the Crown Prosecution Service (CPS) submit an International Letter of Request to the Portuguese authorities. This means British officers can now pursue the inquiry on Portuguese soil and a small team will be based there for several months. They are pursuing similar bureaucratic routes to secure the co-operation of police in three other countries. It is understood that local police officers will arrest or detain suspects in pre-planned operations using British intelligence. Urs Hans Von Aesch (pictured right), a Swiss man who lived in Spain, killed himself in woodland outside Oberburon in Switzerland after abducting and killing five-year-old Ylenia Lenhard (left). Von Aesch has been named as one of many suspects linked to the Madeleine McCann investigation The woodland shrine outside the Swiss town of Oberburon where five-year-old Ylenia Lenhard was abducted and killed by Urs Hans Von Aesch just months after the disappearance of Madeleine McCann The suspects will then be interviewed in the presence of Scotland Yard officers who will direct the lines of questioning. The aim is to examine existing suspicions and establish which suspects can be positively ruled out because they have alibis. Yard detectives have already flown to Switzerland to probe the movements of one of the country's most notorious child snatchers, Urs Hans von Aesch. The 67-year-old, who kidnapped and murdered a five-year-old girl less than three months after Madeleine was abducted, is one of many suspects. He took his own life after killing his victim, who looked remarkably like Madeleine. The Scotland Yard investigation team has grown to 37 people, including murder squad officers, intelligence analysts and administrative assistants. Scotland Yard have today launched a last chance investigation into the disappearance of Madeleine McCann The Portuguese authorities have refused to reopen their inquiry. Officials said they can only reopen the case if there is new evidence, and the new leads do not provide sufficient grounds. But Met detectives strongly believe their leads could, if properly investigated, result in new evidence and perhaps the case being solved. Madeleine was nearly four when she went missing from her family's holiday apartment in 2007 as her parents dined with friends nearby. The shambolic Portuguese inquiry was shelved in 2008 but Scotland Yard began a Home Office-funded review in 2011 following the intervention of David Cameron. He had been lobbied by Madeleine's parents, Kate and Gerry, who were falsely accused by Portuguese police of being behind her disappearance.