Sniffer dogs used in the hunt for murdered schoolgirl April Jones have joined the search of scrubland close to where Madeleine McCann went missing in Portugal seven years ago.
South Wales Police confirmed that two specialist dog handlers and victim detection English springer spaniels Tito and Muzzy were helping with the investigation.
A spokesman said: "Two South Wales Police specialist dog handlers, and victim detection dogs, have been deployed to assist with the investigation into the disappearance of Madeleine McCann.
"The officers are working as part of a small team of British police officers, led by Metropolitan Police Service in conjunction with the Portuguese authorities."
Victim detection dogs can be used for finding hidden bodies as well as searching for people in disasters, and can be used in a variety of locations, including buildings, open areas and vehicles.
Mark Bridger was convicted of murdering April Jones last year. Bridger, a father-of-six, snatched April near her home in Machynlleth, Mid Wales, on October 1 2012. Her body has never been found.
Tuesday saw officers accompanied by their Portuguese counterparts, spend a second day investigating the hilly area in the resort of Praia da Luz on the Algarve.
The large area of scrubland was a hive of activity as police carried out fingertip searches in the undergrowth, scouring the ground for clues as to what happened to Madeleine, who disappeared in May 2007 aged three.
The officers, who were in Metropolitan Police uniform, searched the long grass on their hands and knees, accompanied by one of the two sniffer dogs as they scanned the rubbish-strewn ground.
A British police officer could be seen collecting soil samples from one flat area inside the cordon, which had been marked out with tape while small yellow flags could be seen poking out of the ground in places.
Nearby forestry workers used strimmers to cut back swathes of undergrowth to aid the search.
Specialist teams are also thought to be using ground-penetrating radar equipment to probe the ground, looking for disturbed earth.
The area of land is being guarded day and night by armed local police with dogs, and a large yellow-and-white cordon was put in place ahead of the search.
Local police officers on horseback patrolled it while others walked up and down with German shepherd dogs.
A number of small tents have been erected inside the cordon and a number of Portuguese police vans could be seen on top of a large mound in the middle of the area, which overlooks the sea.
The land, a few minutes' walk from the Ocean Club resort apartment where Madeleine was staying with her family, has been searched before.
TV crews and journalists from around the world have gathered as the search - seen as one of the biggest developments in the investigation in recent years - takes place.