Gerry and Kate McCann leave the court in Lisbon June 16, 2014. Gerry and Kate McCann, the parents of missing British girl Madeleine McCann, appeared at a Lisbon court after they launched libel action against a Portuguese former police chief, who said in a book that Madeleine's parents covered up the death of their daughter. REUTERS/Rafael Marchante (PORTUGAL - Tags: SOCIETY CRIME LAW) 

Members of Scotland Yard clean an area during the search for missing British girl Madeleine McCann in Praia da Luz, near Lagos, June 7, 2014. McCann was three when she disappeared from her room at the Praia da Luz holiday resort in the Algarve in May 2007 while her parents were dining with friends at a nearby restaurant, prompting a global hunt and worldwide headlines. REUTERS/Carlos Vidigal (PORTUGAL - Tags: SOCIETY CRIME LAW) 

A member of Scotland Yard works at an area during the search for missing British girl Madeleine McCann in Praia da Luz, near Lagos, June 7, 2014. McCann was three when she disappeared from her room at the Praia da Luz holiday resort in the Algarve in May 2007 while her parents were dining with friends at a nearby restaurant, prompting a global hunt and worldwide headlines. REUTERS/Rafael Marchante(PORTUGAL - Tags: SOCIETY CRIME LAW) 

Members of Scotland Yard insert a camera inside a sewer during the search for missing British girl Madeleine McCann in Praia da Luz, near Lagos, June 7, 2014. McCann was three when she disappeared from her room at the Praia da Luz holiday resort in the Algarve in May 2007 while her parents were dining with friends at a nearby restaurant, prompting a global hunt and worldwide headlines. REUTERS/Rafael Marchante(PORTUGAL - Tags: SOCIETY CRIME LAW) 

Members of the Portuguese police arrive to guard an area in Praia da Luz, near Lagos, June 2, 2014. Police investigating the 2007 disappearance of British girl Madeleine McCann on Monday have sealed off an area of scrubland in the Portuguese resort where the three-year-old went missing. McCann disappeared from her family's holiday apartment in Praia da Luz in May 2007 while her parents dined with friends at a nearby restaurant, prompting a global search and headlines worldwide. REUTERS/Carlos Vidigal 

Kate and Gerry McCann pose with a computer generated image of how their missing daughter Madeleine might look now, during a news conference in London May 2, 2012. Madeleine McCann went missing from a holiday villa in southern Portugal five years ago as her parents dined with friends. REUTERS/Andrew Winning 

Kate McCann, whose daughter Madeleine went missing during a family holiday to Portugal in 2007, attends a news conference at the launch of her book in London May 12, 2011. REUTERS/Chris Helgren 

Kate and Gerry McCann hold hands as they speak about their missing daughter at a news conference in London May 2, 2012. Madeleine McCann went missing from a holiday villa in southern Portugal five years ago as her parents dined with friends. REUTERS/Andrew Winning 

People walks near a billboard of Madeleine McCann at Praia da Luz tourist resort, April 5, 2009, where Madeleine went missing. Gerry McCann, father of Madeleine, is at the resort to film a documentary re-enacting the May 3, 2007 disappearance of his daughter Madeleine, according to the family's press officer Clarence Mitchell. REUTERS/Hugo Correia 

Clarence Mitchell, the spokesman of Kate and Gerry McCann, the parents of missing British girl Madeleine McCann, shows a sketch of a man believed to have abducted Madeleine from the family's apartment in Praia da Luz in Portugal, during a news conference in London January 20, 2008. REUTERS/Alessia Pierdomenico 

Robert Murat (C) prepares to make a statement with Michaela Walczuch (L) and lawyer Louis Charalambous (R) outside the High Court in central London July 17, 2008. Murat, who was named as an official suspect in the disappearance of British girl Madeleine McCann in Portugal, has accepted a settlement with a number of UK newspapers, local media reported. REUTERS/Toby Melville 

Kate and Gerry McCann, parents of missing British girl Madeleine McCann, hold a poster during a news conference in Berlin June 6, 2007. Gerry and his wife Kate are visiting Germany to meet politicians later on Wednesday. The poster reads 'Look into my eyes - Madeleine McCann was abducted in Praia da Luz, Portugal on May 3, 2007'. REUTERS/Alex Grimm 

Kate and Gerry McCann, parents of missing British girl Madeleine McCann, hold up similar sleep wear which their daughter was wearing on the night of her abduction, during a news conference in Berlin June 6, 2007. Gerry and his wife Kate are visiting Germany to meet politicians later on Wednesday. REUTERS/Alex Grimm 

A poster of missing four-year-old Madeleine McCann is seen on a Police Republican Guard near Lagos June 2, 2007. REUTERS/Nacho Doce 

Gerry MacCann, father of the missing British girl Madelaine McCann, looks at messages of support near their home in Rothley, central England, May 21, 2007. REUTERS/Darren Staples 

Portuguese forest rangers search for missing three-year-old Madeleine McCann in a forest near a Portuguese beach resort in the southern province of Algarve May 8, 2007. Police are investigating whether a paedophile ring ordered the kidnap of the three-year-old British girl who vanished from her bed five days ago in southern Portugal, daily Correio da Manha reported on Tuesday. McCann is believed to have been abducted from her apartment on May 3 in Praia da Luz, a popular resort in the Algarve, just yards away from where her parents were dining. REUTERS/Melanie Maps 

Portuguese policemen work at a Portuguese beach resort in the southern province of Algarve May 5, 2007. A British girl who disappeared from her bed in the Portuguese beach resort while her parents dined nearby was kidnapped, police said on Saturday. Police believe three-year-old Madeleine McCann is still alive and have a drawing of a suspect based on evidence from witnesses, said Guilhermino Encarnacao, head of the judicial police in the Faro area of the Algarve. REUTERS/Vasco Celio 

Gerald McCann (L) and Kate MacCann, parents of Madeline McCann, talk to the journalists in the southern province of Algarve May 4, 2007. A three-year-old British girl may have been kidnapped from her bed in a Portuguese beach resort while her parents dined nearby, family friends and a police source said on Friday. REUTERS/Melanie Maps