After a three-day hunt for evidence in the disappearance of Madeleine McCann came to a close in Portugal on Thursday, authorities have uncovered a “relevant clue,” local newspaper Correio de Manhã reported. With sniffer dogs, a tree-cutter, and other equipment, police searched the Algarve reservoir, some 30 miles from the Praia de Luz resort—the last place the British 3-year-old toddler was spotted 16 years ago. Prime suspect 45-year-old Christian Brueckner, who is currently jailed in Germany for raping an older woman in Portugal, allegedly visited the reservoir “some days” after McCann vanished. Cops said the search “resulted in the collection of some material that will be subject to the competent expertise,” which will be “handed over to the German authorities.” What the important clue is remains unclear. Brueckner has not faced any charges in the case and has denied any involvement.