Madeleine McCann police arrive in Portugal

In the latest stage of the investigation into the disappearance of Madeleine McCann, police today commissioned a Portuguese air force helicopter to fly low over Praia da Luz taking photographs of areas of interest to the inquiry.

An Alouette helicopter was seen flying above the beach and other areas close to where Madeleine disappeared in May 2007.

It comes as work is planned to search the area around the holiday apartment the family were staying in.

Ground-penetrating radar is expected to be used to assess certain areas, including a road that had been dug up at the time 3-year-old Madeleine vanished.

British detectives are currently in the Algarve and this morning met with counterparts from the Policia Judiciaria.

Neither country's officers would offer a view on how the almost four-hour meeting went.

Madeleine McCann's parents have hit out at the coverage of the latest developments in the investigation into the disappearance of their missing daughter.

It is thought that friction has developed between police teams over the media coverage of the story.

In a statement on their Find Madeleine website, Kate and Gerry McCann said: "Media interference not only makes the work of the police more difficult, it can potentially damage and destroy the investigation altogether - and hence the chances of us finding Madeleine.

"As Madeleine's parents, this just compounds our distress."

Search teams are expected to start excavating a number of sites in Praia da Luz after they were given permission by Portuguese authorities.

British detectives are about to begin meeting with Portuguese officers over the Madeleine McCann investigation in Faro.

British detectives investigating the disappearance of Madeleine McCann tonight arrived in Portugal as part of the ongoing investigation to establish what happened to her.

Det Chief Supt Andy Redwood, who is leading the inquiry, traveled to the Algarve with a team of officers a day after the Metropolitan Police confirmed their investigation is moving towards the next phase.

It may include a fresh search of land around the apartment the three year old went missing from in May 2007. A Met spokesman declined to comment.

Read: Police - 'Activity' in hunt for Madeleine to start in weeks

British police officers investigating the disappearance of Madeleine McCann reportedly want to search three locations in Portugal.

It is believed Scotland Yard want to search three locations near Ocean Club Apartment, where Madeleine went missing from, including wasteland where a witness saw a man carrying a child, a road which was under construction at the time she went missing and the nearby beach.

ITV News Correspondent Juliet Bremner reports:

Read: Police say 'activity' in hunt for Madeleine to start in weeks

Metropolitan Police Assistant Commissioner Mark Rowley has said in an open letter that "activity" in Portugal will start in "forthcoming weeks" in the search for Madeleine McCann.

Earlier today Portuguese police sources told ITV News that British detectives investigating the disappearance of Madeleine had been granted permission to excavate two sites at the Algarve resort where she vanished seven years ago.

Clarence Mitchell, spokesman for Kate and Gerry McCann, said Madeleine's parents are "being kept fully informed" amid reports that British police are to start digging for evidence in the Portuguese resort where the 3-year-old went missing in 2007.

British police's request to search a number of sites in Portugal is thought to be among a series of demands made in connection with the disappearance of Madeleine McCann.

The excavations, which are expected to be conducted by forensic experts, are not thought to necessarily be in connection with a search for the youngster's body or remains.

Detectives from Scotland Yard are expected to be in Portugal for the searches, but it is not thought that Madeleine's parents Kate and Gerry will return to Praia da Luz.

Scotland Yard have refused to comment on reports about the latest development in the investigation.

British detectives investigating the disappearance of Madeleine McCann have been granted permission to excavate two sites at the Algarve resort where she vanished seven years ago, Portuguese police sources have told ITV News.