Madeleine's parents, Kate and Gerry McCann, along with their three children, including Madeleine and twins Sean and Amelie, were on vacation in Praia da Luz, Portugal, when Madeline was taken from her bed on May 3, 2007. The family was staying in a ground-floor apartment.
In 2020, German police named convicted child abuser and drug dealer Christian Brueckner, 45, as a suspect in the 3-year-old's disappearance, though Brueckner, a German citizen, continues to deny involvement in the case.
In fact, the convicted criminal claims he was having sex with a woman in his camper van on the night of May 3, miles away from the scene of Madeleine's abduction, before driving the woman to an airport in Faro, according to Sky News.
He also claimed that the woman he was with at the time, whose name he could not remember, would back up his statements, Sky News reported.
Brueckner is currently serving time in a German prison for drug crimes. He also has a pending seven-year sentence connected to the 2005 rape of a 72-year-old American woman in Praia da Luz.
Last month, Portuguese prosecutors formally accused the latest suspect in the investigation. They didn’t name the suspect, in line with Portuguese privacy laws, but said they were acting on a request by German authorities and in coordination with British investigators.
German prosecutor Hans Christian Wolters, who is leading the investigation with Portuguese and British authorities, told Sky News that if Brueckner has a legitimate alibi that could exonerate him, he would share it with authorities.
"So far he has told us nothing, he's given us no alibi," Wolters told the outlet. So, we can only work on the evidence we have found so far in our investigation. And there was nothing to exonerate him."
Kate and Gerry McCann issued a Tuesday statement marking 15 years since their daughter went missing.
"This year we mark fifteen years since we last saw Madeleine. It feels no harder than any other but no easier either. It’s a very long time," they wrote in a joint statement posted to Facebook. "Many people talk about the need for ‘closure’. It’s always felt a strange term. Regardless of outcome, Madeleine will always be our daughter and a truly horrific crime has been committed. These things will remain."
They continued: "It is true though that uncertainty creates weakness; knowledge and certainty give strength, and for this reason our need for answers, for the truth, is essential. We are grateful for the ongoing work and commitment of the UK, Portuguese and German authorities as it is this combined police effort which will yield results and bring us those answers."
The parents also thanked supporters for their well-wishes.
Fox News' Rebecca Rosenberg and The Associated Press contributed to this report.