The meeting between British and Portuguese police over the Madeleine McCann case is routine and there are no plans for any imminent arrests.
Met Police want to speak to a number of men about a large number phone calls they made in the area on the night the child vanished.
The Portuguese inquiry into the disappearance of Madeleine McCann has been reopened amid new leads in the case.
British police investigating the disappearance of Madeleine McCann have sent a third letter of request to Portuguese authorities.
Scotland Yard stressed that the document, sent on Friday, was a routine part of their inquiry but would not reveal what the letter said.
The letters of request are the official channel through which British investigators can ask their Portuguese counterparts to carry out pieces of work on their behalf.
Deputy Assistant Commissioner Martin Hewitt said that so far no requests to carry out interviews or arrests had been made.
Six years since Madeleine McCann, from Leicestershire, went missing in Praia da Luz, UK police want their Portuguese counterparts to search the homes of three former employees of the resort the family was staying at and examine their bank accounts.
Detectives from both countries are running their own investigations, but a team from Scotland Yard made the request after flying to Portugal this week, having formally requested help from their foreign counterparts.
The men of interest to Police are believed to have been working at the Ocean Club complex at the time of the McCann's visit in 2007, according to the Daily Mirror.
It is believed they were behind several burglaries in the weeks leading up to the three-year-old's disappearance.
British detectives investigating the disappearance of Madeleine McCann have flown to Portugal to talk to officers about potential leads.
The Scotland Yard team want to question three suspected burglars who they believe may have been involved in Madeleine's disappearance almost seven years ago.
The three men were making a large amount of phone calls to each other during the time that Madeleine vanished.
The officers arrived in the Algarve yesterday and Kate and Gerry McCann are being kept informed of developments.
Metropolitan Police officers have today visited the Portuguese city of Faro to discuss the Madeleine McCann case with police there, ITV News understands.
The CPS has sent an International Letter of Request to Portuguese police seeking permission to make the first arrests in the hunt of Madeleine McCann, the Mirror reports.
A spokesman for Kate and Gerry McCann said the letter was "significant" but they were not building their hopes up.
Read more on this story on the National website.
The Metropolitan Police have confirmed that a formal request for help in the Madeleine McCann case has been sent to Portuguese authorities.
In a statement made tonight, a police spokesperson said:
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 (week commencing 6 January) in connection with Operation Grange.
British detectives have formally requested help from Portuguese authorities as part of their investigation into the disappearance of Madeleine McCann.
It is believed investigators from Scotland Yard want police in Portugal to question three burglars operating in the resort where the McCanns were staying at the time of her disappearance in 2007.
A libel case brought by the parents of missing Madeleine McCann is expected to end today.
Kate and Gerry McCann from Rothley in Leicestershire are pursuing former Portuguese police detective Gonçalo Amaral for claims he made in a book about her disappearance.
Madeleine, who was nearly four at the time, disappeared from a holiday apartment in the resort of Praia da Luz in the Algarve on May 3 2007 as her parents dined at a nearby restaurant with friends.