The lawyer acting for Madeleine McCann's parents has demanded a meeting with police in Portugal to establish what new evidence there is that she is dead.
The family have become increasingly frustrated at the lack of transparency in the joint British-German-Portuguese investigation and want to know why they say there is evidence that a German paedophile killed Madeleine but not enough proof to charge him.
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On Sunday, it emerged that key information has been passed to Portuguese police, with a senior source telling the BBC it is "very important" and "significant", confirming that Christian Brückner is the prime suspect in Madeleine's abduction in 2007.
The McCanns hope they can find out what that information is, and their lawyer is planning a meeting with officers from the Policia Judiciaria in Lisbon this week.
"I intend to meet the Portuguese police in the next few days and try to find out what information they have that can support the reopening of the file here," Rogerio Alves said.
"At this time, what I hope is that everybody helps to find the truth instead of hiding information or keeping information for themselves. This is not a competition between the police departments. We all have to go forwards to find the truth. I intend to get answers on these matters this week."
It is understood that Kate and Gerry McCann are concerned about conflicting statements from German prosecutor Hans Christian Wolters over whether they actually have proof that Madeleine is dead.
Last week, Braunschweig state prosecutor Wolters said: "After all the information we got, the girl is dead. We have no information that she is alive." But over the weekend he told the Sunday Mirror: "Because there is no forensic evidence, there may be a little bit of hope."
Further muddying the waters in an interview with the Sunday Times, Wolters said a key piece of evidence obtained by his team provided "100 per cent" certainty that Madeleine is no longer alive.
"In terms of the investigation, and the parents' hopes for justice, last week was a lost week," said Alves. "All the police should be doing is trying to solve the case. I want to see full co-operation between the police forces."
While Madeleine's disappearance is being treated as a missing persons investigation by the Metropolitan Police and as a murder investigation by the German prosecutor, the case was closed in Portugal in 2008 with no one ever charged over the crime.
Now it is hoped that the evidence may be strong enough to warrant the case being officially reopened.
"According to Portuguese law, if the Portuguese prosecutor has new information about the crime he should reopen it," said Alves.
"I don't know how strong the new evidence is, so I don't know what the Portuguese prosecutor is going to do. I want to find out if there are new leads for them to chase. I want to know what is being done."