Police probing Madeleine McCann’s disappearance are testing soil samples to see if they match dirt found in their prime suspect’s camper van.
Detectives believe they have a good chance of proving Christian Brueckner’s VW Westfalia was at Barragem do Arade reservoir in Portugal, around the time the youngster went missing.
They are waiting for comparisons of samples already on file with earth taken from 2ft-deep bore holes made during a three-day hunt last month.
German prosecutors first connected Brueckner, 45, to the remote reservoir near Silves through mysterious photo evidence that has not been made public.
And sources say proving the German visited Barragem do Arade in May 2007 could be pivotal to their case.
One well-placed source said: “Photos led German police investigating Maddie’s disappearance to the reservoir.
“One of their focuses now is to close the net around Brueckner by showing through soil sample analysis that his van was there.
“A positive match of the soil they already have from the vehicle with the earth they removed during the search last week will be another important piece of evidence against him.
“It will be a slight setback if the forensics people don’t get a match but at this stage investigators remain hopeful.
“The search that took place last week would never have been requested and authorised if the motive for it hadn’t been well supported.”
The reservoir is a 40-minute drive from Praia da Luz, where Madeleine vanished from her parents’ holiday apartment in May 2007.
Kate and Gerry McCann, from Rothley, Leics, are being kept updated on the German investigation by Scotland Yard.
German and Portuguese search teams spent three days at Barragem do Arade last month.
It was the first overseas-led search since British police dug for clues on waste ground in Praia da Luz in June 2014.
Brueckner’s friend Michael Tatschl claimed in 2020 that the German often visited a reservoir half an hour from Praia da Luz.
Barragem do Arade was searched twice in February and March 2008 by divers hired by a Portuguese lawyer.
Brueckner was dramatically named as the prime suspect in Madeleine’s disappearance in June 2020.
The pervert, who is serving a jail term in his home country for raping a pensioner in Praia da Luz, denies any involvement.
He was awaiting trial for a string of rapes and child sexual assaults allegedly committed in Portugal.
But those charges were dramatically dropped last month after a court ruling over who had jurisdiction in the case.
They were originally filed by prosecutors in Braunschweig because he previously lived in the city in 2016.
But Brueckner’s lawyer Friedrich Fuelscher argued he was actually living in a warehouse in Neuwegersleben, Lower-Saxony.
A court in Braunschweig ruled in his favour, saying it had no jurisdiction over the case.
But prosecutors are confident the ruling will be overturned when they appeal it in Braunschweig’s Higher Regional Court.
