It is a case which shocked the nation and the world - and 15 years on from the night Madeleine McCann disappeared, her fate remains a mystery.
A family holiday turned into every parent’s worst nightmare when three-year-old Madeleine, who was days away from her fourth birthday, vanished from her bed in an apartment at the Ocean Club in Praia da Luz, Portugal.
The investigation has had plenty of twists and turns, with false leads and reported sightings of her all over Europe and further afield.
However, German national Christian Brueckner has now been named an “arguido” or a named suspect by the Portuguese authorities.
These are some of the key events in the case over the past 15 years.
3 May: Kate and Gerry McCann, from Rothley, Leicestershire, leave their children asleep in their holiday apartment in Praia da Luz in southern Portugal while they dine with friends at a nearby tapas restaurant.
Nothing is amiss when Mr McCann checks on the youngsters just after 9pm, but when his wife goes back at about 10pm she finds Madeleine missing.
Jane Tanner, one of the friends dining with the McCanns, reports having seen a man carrying a child earlier that night.
5 May: Portuguese police say they believe Madeleine was abducted, but is still alive and in the country.
9 May: A Norweigian woman on holiday in North Africa claims to see a girl matching Madeleine’s description at a petrol station in Marrakech, Morocco. The girl was said to have asked the man she was with in English, “Can we see mummy now?” The sighting was reported to police in Spain, where the woman lived, and in Portugal. It was to be one of several reported sightings in the country.
14 May: Detectives take Anglo-Portuguese property developer Robert Murat in for questioning and make him an “arguido”, or formal suspect – but this is later withdrawn.
30 May: Madeleine’s parents meet Pope Benedict XVI
17 June: Portuguese police concede that vital forensic clues may have been destroyed hours after Madeleine’s disappearance as the scene was not properly protected.
21 June: Security is tightened in Valletta, Malta following five reported sightings on the island.
31 July: British sniffer dogs arrive in Praia da Luz
11 August: Exactly 100 days after Madeleine disappeared, investigating officers from the Portuguese police publicly acknowledge for the first time that she could be dead.
7 September: During questioning of Mr and Mrs McCann, detectives make them both “arguidos” in their daughter’s disappearance – but this is also later withdrawn.
9 September: The McCanns fly back to England with their two-year-old twins Sean and Amelie.
21 July: The Portuguese authorities shelve their investigation and lift the “arguido” status of the McCanns and Robert Murat.
12 May: Kate McCann publishes a book about her daughter’s disappearance, on Madeleine’s eighth birthday.
Scotland Yard launches a review of the case after a request from Home Secretary Theresa May, supported by Prime Minister David Cameron.
25 April: Scotland Yard detectives say they believe Madeleine could still be alive, release an age-progression picture of how she might look as a nine-year-old, and call on the Portuguese authorities to reopen the case, but Portuguese police say they have found no new material.
4 July: Scotland Yard confirms it has launched its own investigation, Operation Grange, into Madeleine’s disappearance two years into a review of the case. It has “genuinely new” lines of inquiry and has identified 38 people of interest, including 12 Britons.
24 October: Portuguese police confirm that a review of their original investigation has uncovered new lines of inquiry, and they reopen the case.
29 January: British detectives fly to Portugal amid claims they are planning to make arrests.
3 June: Sniffer dogs and specialist teams are used to search an area of scrubland close to where Madeleine went missing.
12 December: Detectives begin questioning 11 people who it is thought may have information on the case.
16 September: The Government discloses that the investigation into the disappearance of Madeleine McCann has cost more than £10 million.
28 October: Scotland Yard cuts the number of officers working on the inquiry from 29 to four.
30 April: The McCanns prepare to mark 10 years since their daughter’s disappearance with a BBC interview in which they vow to do “whatever it takes for as long as it takes” to find her.
15 March: Netflix releases a documentary, ‘The Disappearance of Madeleine McCann’, which reignites speculation about Madeleine’s whereabouts.
3 May: Local media reports say Portuguese detectives are investigating a foreign paedophile as a suspect in the abduction of Madeleine.
3 June: Police reveal that a 43-year-old German prisoner, later named as Christian Brueckner, has been identified as a suspect in Madeleine’s disappearance. He has always maintained he had nothing to do with Madeleine’s disappearance.
28 July: German police search an allotment plot on the outskirts of Hanover in connection with their investigation of a suspect in the disappearance Madeleine.
4 June: Scotland Yard’s Operation Grange, which had received £12.3 million in funding up to April 2020, is still a missing person inquiry as detectives have no “definitive evidence whether Madeleine is alive or dead”.
4 May: Kate and Gerry McCann post a statement on the Official Find Madeleine Campaign website saying they still cling to the hope of seeing their daughter again as they prepare to mark her 18th birthday on 12 May.
31 January: A new documentary airs on German TV channel SAT 1. The team behind it say they have uncovered new findings in the case.
19 March: reports say Operation Grange will close its investigation later this year.
21 April: Christian Brueckner, now 44, is made an “arguido”, a formal suspect, by Portuguese authorities.
22 April: Kate and Gerry McCann release a statement on the Official Find Madeleine Campaign page welcoming the latest development and say they have not given up hope Madeleine is still alive and that they “will be reunited with her”.
2 May: On the day before the 15th anniversary of her disappearance, reports suggest that suspect Christian Brueckner could be charged by the end of summer. Detectives have told potential witnesses to be on standby to give evidence in a German courtroom.
Friends who knew Brueckner when he lived in Portugal have been told that charges could be imminent. One former friend said: “I got a call from the Germans asking questions about a previous statement I made. They said I should be prepared to come to Germany, possibly at the end of the summer. They said they were hoping to charge Christian with something but didn’t go into any more detail.”
2 May: Madeleine’s parents say it is “essential” to learn the truth about what happened to their daughter, and in a message on the campaign page say: “It is a huge comfort to know that regardless of time passed, Madeleine is still in people’s hearts and minds.”
3 May: A German prosecutor reveals in an interview on Portuguese television that investigators have found new evidence against Christian Brueckner. Hans Christian Wolters said there was “some new evidence, not forensic evidence, but evidence.”