A German investigation into the 2007 disappearance of the British toddler Madeleine McCann could continue until next year, according to the state prosecutor in the city of Braunschweig. Officials in Faro, Portugal, said on Thursday that the convicted rapist Christian Brückner, 44, is an arguido, or “formal suspect” – the first time Portuguese authorities have officially identified a suspect in the case since Kate and Gerry McCann, the toddler’s parents, were declared such in 2007. They were formally cleared of suspicion in 2008. Officials in the northern German city of Oldenburg, where Brückner is serving seven years for raping an American pensioner in 2005 in the same area of Portugal’s Algarve region where Madeleine went missing, confirmed on Friday they had informed the prisoner of his new status. Madeleine’s parents said they “welcomed the news that the Portuguese authorities have declared a German man an arguido”. They said in a statement: “Even though the possibility may be slim, we have not given up hope that Madeleine is still alive and we will be reunited with her.” However, the state prosecutor in Braunschweig, Hans Christian Wolters, who has been investigating Brückner over Madeleine’s disappearance and four other alleged offences since 2020, said the news from Portugal was unlikely to indicate a breakthrough in the 15-year-old case. “We note the announcement from Faro, but it does not affect our own work in a significant way,” Wolters said. Asked if it were possible that Brückner was about to be charged in Portugal and extradited there from Germany, Wolters said he believed it was “rather unlikely there will be an indictment in Portugal”. It will be the 15th anniversary of Madeleine’s disappearance from her bed in a holiday apartment in the resort of Praia da Luz on 3 May, and Portugal has a 15-year statute of limitations for crimes with a maximum prison sentence of 10 years or more. The arguido classification “appears to have a procedural background in Portugal”, said Wolters. “A statute of limitations can be avoided that way.” Brückner’s lawyer, Friedrich Fülscher, told the German newspaper Bild that the Portuguese decision was a “procedural trick”. German police said in June 2020 that Madeleine was assumed dead and that Brückner was likely responsible for her disappearance. However, British officers continue to treat it as a missing persons case and her parents “still hope” Madeleine is alive. Germany, unlike Portugal, does not have a statute of limitations for murder, and the state prosecutor in Braunschweig is investigating Brückner for five separate alleged offences. They include three cases of rape and two cases of child molestation, the most recent being in 2017 where Brückner is alleged to have exposed himself and masturbated in front of a group of children. Wolters said his office would make an announcement regarding the next step towards a possible prosecution at the end of May, but “the end of our investigations into the McCann case is not yet in sight” and could continue into 2023. If Brückner were charged over the other alleged offences in Germany, likely to be at the end of the summer or in early autumn, he would need to either personally consent to be trialled in Germany or Portugal or the prosecution would need to reissue extradition papers from Italy, where the suspect was last arrested in September 2018 – a process that could take between two weeks and several months. If the suspect in the McCann case was to be charged in Portugal, Portuguese authorities would need to take the same bureaucratic step. Different national prosecutors in Europe can investigate criminal offences in parallel, although legal agreements in the EU are designed to avoid individuals being charged over the same crimes more than once.