In a statement, the PJ said it was executing a European Investigation Order on behalf of the public prosecutor's office in the German city of Braunschweig, which in 2022 formally identified German citizen Christian Brueckner as an official suspect in McCann's disappearance.
It added that "a wide range of investigations, namely search warrants" would be carried out between June 2-6 in Portugal's Municipality of Lagos and all evidence seized would be handed over to Germany's Federal Criminal Police Office (BKA).
The search for traces of the child's body will focus on an area between Praia da Luz, a civil parish belonging to Lagos, and one of the houses where Brueckner lived when McCann disappeared 18 years ago, according to news reports by CNN Portugal and German newspaper Bild.
Braunschweig prosecutors told Reuters "criminal procedural measures" related to the McCann case were taking place in Portugal involving the BKA and Portuguese law enforcement but did not provide further details.
London's Metropolitan Police said they were aware of searches carried out by the BKA in Portugal, adding the force was not present there but would "support our international colleagues where necessary".
German police said in June 2020 that McCann was assumed dead and that Brueckner was likely responsible.
Brueckner has denied any involvement and has not been charged with any crime related to the case.
The convicted child abuser and drug dealer is behind bars in Germany for raping a 72-year-old woman in the same area of the Algarve.
The last search for McCann was carried out in May 2023, when the police combed an inland reservoir in the Algarve but did not find anything.
