Madeleine McCann disappeared on the evening of Thursday, 3 May 2007 in the resort of Praia da Luz in the Algarve, Portugal, just days short of her fourth birthday. The British girl was on holiday with her parents, Kate and Gerry McCann, and siblings when she disappeared from an apartment in the central area of the resort. Madeleine's parents have said that they left her unsupervised in a ground floor bedroom with her two-year-old twin siblings while they ate at a restaurant about 120 metres away.[1]

The initial investigation by the Polícia Judiciária (Portuguese criminal investigation police) concluded that she had been abducted.[2] After further investigation, they subsequently stated that there was a strong hypothesis that she might have died in her room.[3][4] During the investigation there were a number of unconfirmed claimed sightings of Madeleine in Portugal and elsewhere and additional scientific evidence was obtained.

Robert Murat, a local resident, was given arguido (suspect) status on 15 May.[5][6] Nonetheless, police investigating the disappearance admitted on 17 August that the investigation was nowhere near a breakthrough.[3] Kate and Gerry McCann were also named as arguidos on 7 September, but were allowed to fly back to the United Kingdom on 9 September.[7][8][9] The investigation involved the cooperation of the British and Portuguese police and demonstrated the differing methodologies employed by each, with regard to such aspects as the amount of information released to the public and the legal status of those involved in the case.

The disappearance and its aftermath are notable for the breadth and longevity of the media coverage. This was initially due to the active involvement of the parents in publicising the case and to several awareness-raising campaigns by international celebrities and, latterly, to the interest that arose from the parents being named as suspects. The event generated international media attention with controversy surrounding the Portuguese-led police investigation and the actions of Madeleine's parents. There has also been criticism of the extent and nature of the publicity and of the reporting of the disappearance in both the Portuguese and British media.