Disappearance of Rui Pedro Teixeira Mendonça

Rui Pedro Teixeira Mendonça, born 28 January 1987, was an 11-year-old boy living in Lousada, in northern Portugal, when he disappeared on 4 March 1998. That afternoon, around 2:00 p.m., he rode his bicycle to his mother's workplace and asked to spend the afternoon in a car with a 22-year-old family acquaintance, lorry driver Afonso Dias. His mother refused and told him to play in a nearby vacant lot instead. Mendonça did not return; his tutor alerted his parents after he missed a scheduled 5:00 p.m. lesson, prompting an immediate search.

Because Mendonça had mentioned plans to meet Dias, police questioned him early in the investigation; Dias said only that he did not know where the boy was and that police "should close the borders." Mendonça's cousin later told police that Dias had proposed introducing the boys to a sex worker, though the cousin said he had not gone with them that day. According to testimony a sex worker gave years later, Dias brought Mendonça to her that afternoon and offered to pay her to have sex with him; she said the boy was visibly distressed and told her Dias had forced him to come, and that Dias then drove off with him again. She was not able to formally identify Dias by name until 2011. Investigators also examined a family photograph taken at Disneyland Paris in April 1998 that reportedly showed a boy resembling Mendonça, though the lead went nowhere. In September 1998, Mendonça was identified among the children pictured in material seized when police raided the "Wonderland Club" child pornography ring in Operation Cathedral.

The investigation drew sustained criticism from Mendonça's family and Portuguese journalists, who said police were slow to pursue witnesses, did not formally take testimony from the sex worker for years, and mishandled evidence. In a 2002 reconstruction of the day of the disappearance, one of the case's chief inspectors later said Dias' account did not hold up. Oversight of the case moved between several investigative teams and prosecutorial bodies, including Portugal's Central Department of Investigation and Penal Action, which took over the case in September 2003. In 2012, a police inspector who had worked on the original investigation testified that he had lied to the press in 2005 when he accused the family of concealing that Mendonça had epilepsy; he received a 25-day disciplinary suspension.

Dias was tried on a kidnapping charge; his trial opened in November 2011, and he was acquitted in March 2012. He was later sentenced, on 3 October 2014, to three years in prison for kidnapping Mendonça, jailed in March 2015 after an arrest warrant was issued, and released in March 2017 after his sentence was reduced for good behavior. Dias has said he does not know what happened to Mendonça and, after his release, described his prosecution as unjust.

Mendonça's whereabouts have never been established. Police have said they suspect he was murdered by his abductors after being sexually abused on camera for the child pornography ring, but this has not been confirmed, and beyond Dias' kidnapping conviction no one has been charged in relation to his suspected murder or the abuse images in which he was identified. His mother, Filomena Teixeira, has campaigned publicly for decades and founded an association for families of missing children in 2007. Mendonça was declared legally dead in 2019.