The search for the body of Madeleine McCann has centred on wells in the Algarve region of Portugal, where the British pre-schooler vanished in May 2007.
The latest search has centred on a well on the outskirts of the village of Budens, in the municipality of Vila do Bispo, just 10km from Praia da Luz, where Madeleine was last seen 13 years ago.
Portuguese police, including expert divers, have been searching underground reservoir overgrown by bushes and weeds on an abandoned farm, Daily Mail reports.
The farm is close to a road just a short drive from the Ocean Club resort where Madeleine was staying with her family.
Prime suspect Christian Brueckner is understood to have known the area well.
Portuguese broadcaster RTP claimed detectives have 'fundamental evidence' to be able to prove the 43-year-old German is responsible for Madeleine's disappearance.
News of the latest search comes after detectives undertook searches in wells in Vila do Bispo, a 20 minute drive west of Praia da Luz where the British youngster vanished while on holiday with her family.
RTP has also linked Brueckner, 43, to another missing persons' case in the Algarve resort of Silves.
Last week it was revealed Breuckner had been arrested on suspicion of exposing himself to children in a playground a short drive from Praia da Luz in 2017 when he was on the run from German authorities.
Portuguese newspaper Correio da Manha said no evidence Madeleine's body had been abandoned in the wells had been found.
Brueckner, a convicted child sex offender, was born in Würzburg under a different name believed to be Fischer, Daily Mail reports.
He is currently behind bars in Germany and serving 21 months for dealing drugs in the German resort of Sylt.
His lawyers have reportedly filed a request for him to be released after serving two-thirds of his sentence, but prosecutors fear he may flee the country after his release.
The serial sex offender is also facing a separate sentence for the rape of a 72-year-old American woman in Praia da Luz in 2005.