Madeleine McCann search police are focusing on an area where ground-penetrating radar equipment has picked up an image beneath the soil.
Seven years on from Madeleine McCann's disappearance, British detectives are in Portugal to meet with police.
Gerry McCann has called on the Prime Minister to give his backing for a new law to underpin the recommendations of the Leveson report.
The Metropolitan Police's Detective Chief Inspector Andy Redwood, who is in charge of the hunt for Madeleine McCann, watches police continue to clear and search scrubland in Praia da Luz, Portugal, today.
The search for missing Madeleine McCann continues on wasteland in Praia da Luz, Portugal, as police have applied for an extra seven days to investigate the site.
The two springer spaniels from South Wales Police that are being used at the site were seen sniffing around a flat area of the scrubland that had been marked out with tape this morning.
It is not clear whether they will work over the weekend and officers are not expected to carry out any searches on Tuesday, as it is a public holiday in Portugal.
Sniffer dogs are being used today on scrubland close to where Madeleine McCann went missing in Portugal seven years ago as the search looks likely to go into a second week.
British officers, accompanied by their Portuguese counterparts, were expected to examine the area in Praia da Luz on the Algarve until tomorrow but have applied to the judiciary to spend an extra seven days there.
It is not clear whether they will work over the weekend and nothing is expected to be carried out on Tuesday as it is a public holiday.
Today, two springer spaniels were seen sniffing around a flat area of the scrubland that had been marked out with tape.
Yesterday, forensics officers were seen in an area which was previously hidden by undergrowth, while ground-penetrating radar equipment was used in another.
The area being searched, which is a few minutes' walk from the Ocean Club resort apartment where Madeleine and her family were staying when she went missing in May 2007, saw officers focusing their investigations on a hole which had been previously covered by undergrowth.
British police will spend a fourth day carrying out investigations on an area of scrubland close to where Madeleine McCann went missing in Portugal seven years ago.
Officers, accompanied by their Portuguese counterparts, were expected to probe the area in Praia da Luz on the Algarve until Friday but have applied to spend an extra seven days there.
ITV News Central correspondent Gareth Owen said British police had been granted another seven days to work on the search area in Praia da Luz.
A patch previously examined in the search near Praia da Luz has been scanned again with ground-penetrating radar equipment to probe for disturbed earth.
It was moved along the ground by a woman dressed in black, accompanied by a man who had scanned the area earlier.
The device uses radar pulses to take images of the subsurface of the ground to check for any anomalies.
It can be used to check for disturbances in a variety of substances, including rock, soil, ice and fresh water. It can also detect voids and cracks in buildings and under pavements.
Local forestry workers have been clearing large areas of undergrowth within a scrubland search near the resort where Madeleine McCann went missing in 2007.
Forensic police officers were pictured preparing to examine a hole in an area of wasteland to search for Madeleine McCann in Praia da Luz, Portugal, where she went missing in 2007.
In the last few hours there's been a surge in activity at the site in Portugal where police are searching for missing Madeleine McCann from Leicestershire.
She went missing seven years ago from an apartment in the holiday resort of Praia da Luz in the Algarve.
This morning British police have started using ground penetrating radar at a site a short distance away from the apartment, with the focus around a hole on one part of the site.
ITV News Central Correspondent Gareth Owen has the latest.
There have been a couple of developments here that have taken us and have perhaps taken the police teams by surprise.
At the very edge of the wasteland where officers are searching are a couple of white tents.
Under them is a hole. They found it yesterday, it was covered by a couple of sheets of corrugated iron and then that was covered by some soil.
They dug away and they pulled these sheets apart yesterday and they found this very precise hole in the shape of a square - now, that's of interest to them, they didn't know it was there.
We've seen a couple of police officers in forensic suits inside those tents, we don't know what they've found, we don't know if it is of specific interest but we do know it's something they didn't anticipate when they got here