Madeline McCann Photo: Reuters

Here is a timeline of the key events since Madeleine McCann's disappearance.

2007 

•        May 3 - Kate and Gerry McCann, from Rothley, Leicestershire, leave their three 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 at just after 9pm, but when his wife goes back at about 10pm she finds three-year-old Madeleine missing. Jane Tanner, one of the friends eating with the McCanns, later reports seeing a man carrying a child away earlier that night.

•        May 14 - Detectives take Anglo-Portuguese property developer Robert Murat in for questioning and make him an "arguido", or formal suspect. Officers also search the home he shares with his mother in Praia Da Luz, just 100 yards from where the youngster vanished.

•        May 30 - Mr and Mrs McCann meet the Pope in Rome in the first of a series of trips around Europe and beyond to highlight the search for their daughter.

•        August 6 - A Portuguese newspaper reports that British police sniffer dogs have found traces of blood on a wall in the McCanns' holiday apartment.

•        August 11 - Exactly 100 days after Madeleine disappeared, investigating officers publicly acknowledge for the first time that she could be dead.

•        September 7 - During further questioning of Mr and Mrs McCann, detectives make them both "arguidos" in their daughter's disappearance.

•        September 9 - The McCanns fly back to England with their two-year-old twins Sean and Amelie.

•        October 2 - Goncalo Amaral, the detective in charge of the inquiry, is removed from the case after criticising the British police in a Portuguese newspaper interview.

2008

•        July 21 - The Portuguese authorities shelve their investigation and lift the "arguido" status of the McCanns and Robert Murat.

•        July 24 - Mr Amaral publishes a book about the case, entitled The Truth Of The Lie, in which he alleges that the young girl died in her family's holiday flat on the day she went missing.

•        August 4 - Thousands of pages of evidence from the Portuguese police files in the exhaustive investigation into Madeleine's disappearance are made public. They reveal details of the lines of inquiry pursued by detectives, witness statements and scores of previously unknown sightings of the little girl.

2009

•        January 29 - Nearly £2 million was raised for the official fund to find Madeleine in the first 10 months after she went missing, Companies House accounts show.

•        September 9 - A Portuguese judge bans further sale or publication of Mr Amaral's book following legal action by Mr and Mrs McCann. This injunction is later upheld before being overturned on appeal.

2011

•        May 12 - Mrs 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.

2012

•        April 25 - Scotland Yard detectives say they believe Madeleine could still be alive, release an age-progression picture of how she might look now as a nine-year-old, and call on the Portuguese authorities to reopen the case.

•        April 26 - Portuguese police say they have found no new material that will allow them to reopen their investigation.