A Portuguese police officer rolls up police tape during the search for missing British girl Madeleine McCann in Praia da Luz. Picture: Rafael Marchante

Praia da Luz, Portugal -

Portuguese and British authorities investigating the disappearance of Madeleine McCann on Wednesday concluded their search of a patch of land near the resort in southern Portugal where she vanished seven years ago.

Around 20 investigators spent Wednesday scouring two areas either side of a highway on the outskirts of the Algarve resort of Praia da Luz.

On Wednesday evening, police removed cordons around the search area, took their equipment and left the scene, according to an AFP photographer.

A police source told AFP that the search had been “requested by Scotland Yard”, without giving a reason.

The source added that British police asked the Portuguese authorities to question people of interest to the investigation.

British detectives received authorisation from the Portuguese authorities last month to search near the resort complex where Madeleine disappeared from her bedroom in May 2007 as her parents dined with friends at a nearby tapas restaurant.

Police spent last week using sniffer dogs and ground radar to search another area around 700m from the resort. That search did not lead to any significant discovery, according to the Portuguese media.

The Portuguese investigation into Madeleine's disappearance wound up in 2008. But British police re-examined the evidence and opened their own investigation in July last year, closely followed by the Portuguese authorities.

The case has been kept in the public eye by a high-profile media campaign orchestrated by Madeleine’s parents, Kate and Gerry McCann.

One line of investigation for Scotland Yard is a lone male paedophile who staged a series of sex attacks on young British girls while they were on holiday in the Algarve. - Sapa-AFP