Portugal police have assembled a new team of detectives to assist Scotland Yard's investigation into the disappearance of Madeleine McCann, the British toddler who went missing in Portugal six years ago.
Madeleine McCann was three when she vanished from a holiday apartment in the Algarve region of Portugal in 2007 as her parents ate dinner at a nearby restaurant with friends.
Madeleine's parents, Kate and Gerry McCann, said they found Madeleine missing after having left the children in the home unsupervised while having dinner nearby.
Madeleine's disappearance sparked a global hunt for the toddler, but an investigation by Portuguese police was shelved in July 2008.
The newly assembled Portugal team will make inquires and question witnesses on behalf of Scotland Yard. British police launched a new investigation into Madeleine's disappearance in July and believe she may still be alive, having found no evidence to prove otherwise.
"We have visited Portugal on 16 occasions," said Detective Chief Inspector Andy Redwood. "The Portuguese have worked with us. We are working carefully and closely together now in order to progress this case."
British detectives decided to open a new case after uncovering what they said was new evidence from reviewing 30,000 documents and carrying out new witness interviews.
Thirty-eight "persons of interest" from a number of European countries have been identified by Scotland Yard. Twelve of those are British nationals believed to have been in Portugal when Madeleine went missing, but not all of them are currently living in the U.K.
Among the 38 people whom police will question is Antonio Castela, a 73-year-old cab driver who thinks he may have picked up Madeleine and at least two men and one woman the night after she disappeared.
None of the McCanns' friends who were having dinner with them the night that Madeleine disappeared are among the 38 "persons of interest" in the case.
Kate and Gerry McCann have maintained a website and a 24-hour tipline to keep their daughter's case in the public eye.
Madeleine would have turned 10 years old on May 12 of this year.
ABC News' Jean-Nicholas Fievet contributed to this report.