The Portuguese Attorney General has received a formal International Letter of Request from British detectives investigating the disappearance of Madeleine McCann.
It is thought officers from the Met want to locate and question three burglars who were operating in Praia da Luz after mobile records revealed they had made an unusually high number of phone calls to each other shortly after the little girl disappeared.
Joana Marques Vidal confirmed the letter, which was sent on 10 January had been passed to a Portuguese court for consideration, ITV reports.
Madeleine McCann has been missing since 2007
In the days before Madeleine’s disappearance, the trio in question are reported to have raided another holiday flat in the same resort, awakening a child, but fled after the parents returned.
The Portuguese police attached no significance to the earlier incident, but one theory is that the burglars may have panicked after waking Madeleine by mistake and decided to take her with them, the Daily Mail writes.
Earlier this month a Scotland Yard spokesman told HuffPost UK: “We can confirm that a (second) International Letter of Request (ILOR) has been sent to the Portuguese authorities by the Crown Prosecution Services this week in connection with Operation Grange.”
The Met has refused to give details of the type of assistance requested, though it needs the assistance of local police to pursue the inquiry.
A spokesman for Madeleine’s parents Kate and Gerry McCann described the letter as “significant”, that they believe it indicates an arrest is imminent and that “it’s likely it is the three burglars.”
The first letter requesting help from the Portuguese authorities was sent in in July after the force announced a full investigation into the case
Madeleine, who was then nearly four, disappeared from her family's holiday apartment in Praia da Luz in Portugal's Algarve on May 3 2007, as her parents dined at a nearby tapas restaurant with friends.