They were the first major searches in Portugal in nine years following a June 2014 operation when British police were given permission to carry out digs in Praia da Luz that involved ground-penetrating radar and sniffer dogs trained in detecting bodies.
The digs, carried out by Scotland Yard, were linked to the leading UK police theory at the time that Madeleine died during a break-in and burglars dumped her body nearby.
The 2014 search also failed to produce any evidence pointing to the missing youngster’s whereabouts.
In a smaller operation in July 2020, Portuguese police and firefighters searched three wells for Madeleine’s body but failed to find any trace of her.
A well-placed Portuguese source confirmed this week’s operation was scheduled to begin on Tuesday but said some preparation work might take place beforehand.
He said: “They will be land searches only.
“The main objective is to look for any signs of Madeleine’s body.”
Portuguese police are understood to have agreed to co-operate with the search after it was approved by the country’s judicial authorities following a formal request from German police and prosecutors.
The search is expected to last about three days, unless anything relevant emerges.
Brueckner remains in prison in Germany, where he is serving a seven-year term for rape.
The 48-year-old convicted paedophile had hoped to be released from jail in September but has reportedly been accused of new offences against prison guards.
Sources said the new searches would take place on more than 20 privately owned pieces of land near a ramshackle rented cottage on the outskirts of Praia da Luz where Brueckner spent several years living.
They said the search area would extend from the house eastwards towards an inland area known as Atalaia, in the direction of Lagos.
One said: “The search will take place on 21 privately owned pieces of land which in some cases are open and not fenced off.
“Wells, ruins and water storage tanks will be searched.
“The landowners haven’t had to be asked for permission and they can’t stop the searches from continuing if they turn up because police will be acting with a judicial warrant.”
Another said: “Around 30 German police officers have already arrived in Portugal and will be starting the search tomorrow.
“Portuguese police will also be on the ground.
“We are talking about a rural area with a lot of waste ground. Some of the areas that are going to be looked at have already been searched before.”
The German police team is expected to include forensic experts, who were also present for the May 2023 Arade Dam searches.
It is not yet clear if detectives are acting on a new tip-off about where Madeleine’s body could be.
Portugal’s police force and the country’s attorney general’s office have yet to make any official comment and are not expected to do so until after the search work begins.
