Detectives investigating the disappearance of Madeleine McCann have been granted permission to question eight key suspects.

Police identified the local men after they were traced from phone records linking them to Praia da Luz on the night the missing youngster was last seen alive.

The suspects, three of whom are convicted drug dealers, are believed to have been former employees at the Ocean Club resort.

Analysis of phone data suggests they were in close contact with each other in the hours that followed Madeleine's abduction.

Earlier this year, Britain's most senior police officer Sir Bernard Hogan-Howe said Scotland Yard was closing in on the people who abducted Madeleine McCann after three burglars were identified as the prime suspects in the case.

It was reported that there had been an increase in burglaries in the months before Madeleine vanished. One line of enquiry focused on the possibility that Madeleine may have woken and disturbed burglars at the apartments on the night of the abduction. ‎

Scotland Yard has now asked Portuguese authorities for permission to check the suspects' criminal histories, their friends, the vehicles they used and their bank details.

The suspects will be questioned by Scotland Yard detectives in Portugal after they complete detailed excavation work in the Algarve as part of 'Operation Grange'.

madeleine mccann tent
Scotland Yard detectives move a tent onto an area during the search for missing British girl Madeleine McCann in Praia da Luz, Portugal Reuters

The development comes as British police completed their first week searching wasteland, five minutes walk from the Ocean view apartments where the McCann family were on holiday in May 2007.

An area the size of three football pitches is being investigated using sniffer dogs, digging machines and radar equipment. An underground sewer network is also being scoured for any traces of evidence.

Detectives were due to complete the search today but have been granted an extra week.

Madeleine's parents Kate, 46, and Gerry, 45, who have not travelled to Portugal said they are 'encouraged by the progress'‎ in the ongoing search for their daughter.

Operation Grange was launched after David Cameron ordered a reinvestigation of the Madeleine case in 2011.