The identities of six of the 11 potential witnesses being interviewed in Portugal over missing Madeleine McCann have yet to be made public.
Those we do know include Robert Murat, a Brit who was the first person to be declared a suspect but was never arrested or charged, his wife Michaela Walczuch and her ex-husband Luis Antonio.
Joaquim Marques was today interviewed for the third time while British police sat in.
While Mario Marreiros, who worked at the Ocean Club hotel where Madeleine's family were staying, claims he saw a man acting suspiciously.
ITV News reporter Rebecca Barry has this report:
Some 11 people "will be interviewed as witnesses" by the police searching for missing Madeleine McCann, Good Morning Britain heard.
British and Portuguese "men and women" are expected to be quizzed by the police over what happened to the missing youngster.
British police are expected to arrive in Portugal today to question a number of people over the disappearance of Madeleine McCann.
The three-year-old, from Rothley in Leicestershire, went missing from a holiday apartment in Praia da Luz in Portugal in 2007.
Scotland Yard detectives will be expected to interview Robert Murat, who was arrested as part of the Portuguese police investigation into her disappearance at the time.
As well as questioning seven suspects, four other people will be interviewed as potential witnesses.
British police travelled to Portugal over the summer and spent eight days searching three areas of Praia da Luz, but found no new evidence.
Police are due to arrive in Portugal today to interview seven suspects over the disappearance of Madeleine McCann.
Madeleine, from Rothley in Leicestershire, went missing from a holiday apartment in Praia da Luz in Portugal in 2007, nine days before her fourth birthday.
Scotland Yard detectives will be expected to interview Robert Murat - who was arrested as part of the Portugese police investigation into her disappearance in 2007.
Mr Murat has always denied any involvement.
As well as the seven suspects, four others will be interviewed as potential witnesses.
British officers spent eight days searching three areas of Praia da Luz this summer but found no new evidence.
Eleven people are to be questioned over the disappearance of Madeleine McCann in a fresh investigation by British police.
They include seven potential suspects and four who will be spoken to as witnesses.
British ex-pat Robert Murat, who was the first "person of interest" when three-year went missing in Portugal seven years ago, is one of those police want to re-interview.
His wife, Michaela Walczuck, and her former husband, Luis Antonio, are also understood to be on a list of people identified to give statements to the inquiry run by British police.
The parents of missing Leicestershire girl Madeleine McCann have won £55,000 in libel damages from the Sunday Times over a story which suggested that they had kept evidence from authorities investigating their daughter's disappearance.
Kate and Gerry McCann took action over a front-page article by the newspaper which appeared in October last year.
The McCann's said they would be giving the money to two charities.
The Sunday Times has also agreed to pay the McCanns' legal costs.
British authorities competing to be involved in the search for Madeleine McCann alienated Portuguese forces, according to a previously unpublished report from 2009.
The report by Jim Gamble, former head of the Child Exploitation and Online Protection Centre (CEOP), found so many different UK agencies getting involved damaged relations with Portuguese police.
The report was commissioned by the then Home Secretary Alan Johnson in 2009, and was delivered in 2010. But details of the report were briefed to Sky News today.
Madeleine, from Rothley in Leicestershire, went missing from a holiday apartment in Praia de Luz in Portugal in 2007.
More to follow...
A British woman has told Scotland Yard detectives seeking Madeleine McCann that she overheard a conversation in which a man said: “Why did you bring her here? Now we will have to dispose of the body,” the Sunday Express has reported.
According to the newspaper, the potential key witness has been interviewed several times in Britain and used to live almost opposite the apartment in Praia da Luz on the Algarve, from where Madeleine, three, was taken on May 3, 2007.
The Sunday Express understands the comment was heard several hundred yards from the Ocean Club in a residential area towards the seafront.
Scotland Yard told ITV News it was not prepared to give a "running commentary" of the case and could not comment on the claims made in the Sunday Express.
Gerry McCann has told reporters that he believes the person who abducted their four-year-old daughter Madeleine in Portugal in 2007 could kidnap another child.
He was speaking after a court appearance in Lisbon, where he and wife Kate are pursuing a libel case against Portuguese former police chief Goncalo Amaral over allegations he made in a book about their role in the disappearance of their daughter.
Gerry McCann said that their daughter's kidnapper must have been "laughing" at Amaral's claims that there was no abduction and they hid the girl's body.
"He or she or they may strike again," he said. "There's an unsolved serious crime and there's a series of other crimes against children which have come to light who have been on holiday so at the very least these people need to be brought to justice.
"We don't know if Madeleine is alive or dead but there is no evidence that she is dead and she is a missing child and she is completely innocent."