The prime suspect in Madeleine McCann's disappearance visited a reservoir in Portugal just days after her disappearance, a police informant has claimed.
Fresh searches have seen officers dig a concentrated area of woodland near the banks of the Barragem do Arade, which Christian Brueckner is said to have described as "his little paradise".
The convicted sex offender, 45, visited the beauty spot - possibly with others - "some days" after Madeleine went missing, a former friend alleged to police.
The tip-off reportedly tallied up with photos and videos of Brueckner near the reservoir, and influenced investigators to carry out thorough searches of the area.
Search teams have been provided with maps showing where to excavate based on the tip-off, reported The Times.
Nicola Bulley police may be in breach of guidelines in search for missing mumA source with knowledge of the investigation told the newspaper that detectives believe Madeleine could have been alive for two or three days after she disappeared.
German authorities have not revealed what triggered the latest search operation, but prosecutor for the city of Braunschweig Christian Wolters said they were acting on the basis of "certain tips".
He told German public broadcaster NDR: "We have indications that we could find evidence there. I don't want to say what that is exactly, and I also don't want to say where these indications come from.
"The only thing that I would clarify is that it doesn't come from the suspect - so we don't have a confession or anything similar now, or an indication from the suspect of where it would make sense to search."
The reservoir is around 30 miles away from the holiday resort of Praia da Luz, where Madeleine vanished in 2007 while on holiday with her parent and younger twin siblings.
The latest searches are being carried out at the request of German investigators who believe that their prime suspect, Brueckner, kidnapped and murdered the youngster.
He is currently in prison in Germany for the rape of a woman in Praia da Luz in 2005, and is suspected of further rapes and child sexual abuse committed in the area between 2000 and 2017.
The Sun reported that investigators previously found photos and video of Brueckner at the reservoir. He has reportedly denied any involvement in Madeleine's disappearance.
Personnel spent a number of hours cutting back the undergrowth of a peninsula next to the water on Wednesday, before using shovels to excavate part of the area.
A large section of the Barragem do Arade has been cordoned off since Tuesday morning, around 30 miles from where the three-year-old went missing in 2007.
Seven key questions in Nicola Bulley disappearance that have to be answeredSniffer dogs and rakes have been used by uniformed and plain-clothed officers over the course of two days, before specialist forest workers used strimmers and heavy machinery to cut back the landscape.
It is understood the operation will continue today.
Portuguese lawyer Marcos Aragao Correia previously claimed that criminal contacts had told him that Madeleine's body was in the reservoir, and in 2008 he raised funds for unsuccessful private searches of the water.
Four teams of officers from the Portuguese Policia Judiciaria are involved in the new operation, along with at least 20 of their German counterparts, Portuguese news outlet SIC said.
British officers from the Metropolitan Police are also present while the work is carried out so they can inform Madeleine's parents if there are any developments.
On Tuesday, search teams were seen scouring the banks - hammering away at the ground with pickaxes and combing through small rocks with rakes and spades.
Around a dozen officers with sniffer dogs were also at the site, while the fire service boat took officers onto the water.
Portuguese daily Expresso said that the first day ended with no significant results, and that police had collected some objects including fabrics and garments.
Madeleine's disappearance has attracted enormous media attention since she vanished, and reporters are being kept at arm's length around a mile away from where search activity is taking place.
A no-fly zone has also been imposed over the reservoir.
The new searches come as the Home Office granted an extra £110,000 in funding this financial year for the Metropolitan Police to assist with finding Madeleine, down from just over £300,000 last year.
The total funding given to Operation Grange has been just under £13.1 million since 2011.