Leicestershire Detective Superintendent Stuart Prior returned from the Algarve yesterday after meeting counterparts in Portugal about how the fresh interviews would be conducted.
Madeleine went missing from her family’s holiday apartment in Praia da Luz on May 3 last year while Gerry and Kate McCann ate dinner at a nearby tapas bar with friends.
Detectives have focused on the witness accounts given by the group, the so-called “tapas nine”, to try to establish a timeline of events on that evening.
Supt Prior flew to Portugal to discuss the issue of mutual legal assistance, the process whereby evidence is gathered in one country to help an investigation in another.
A Leicestershire police spokeswoman said: “Since Madeleine’s disappearance, we, together with other law enforcement agencies, have been working closely with the Portuguese authorities.
“Supt Prior has attended a series of meetings with his Portuguese counterparts.
“He went to discuss how the request for mutual legal assistance is to be executed and to seek clarification over elements of the request.”
The process itself could involve Portuguese police writing questions to be put to the friends on their behalf by their British counterparts.
Officers involved in the investigation in the Algarve could still fly to Britain to sit in on the interviews, which are likely to be held at a location in Leicestershire.
The McCanns’ spokesman Clarence Mitchell said: “The sooner this re-interviewing takes place the better. The friends are very keen to help police understand their original statements. No one will be changing their story.”
Meanwhile, an expert on child abduction said a Europe-wide missing-child alert system would have “without doubt” saved Madeleine.
Ms Catherine Meyer, who founded a charity to fight child abduction, called for a single Europe-wide telephone number that parents could ring the moment their child went missing.
The system, similar to the Amber Alert in the US, would flash the child’s details up on television and motorway notice boards. All ports and airports across Europe would also be alerted.
Ms Meyer said: “I am without a doubt sure that if an Amber Alert was in place when Madeleine McCann went missing she would have been found, without a doubt.”
A spokesman for the McCanns said: “Kate and Gerry fully support any effort to increase co-ordination across Europe in the case where a child has gone missing.
“They welcome anything that can lead to greater co-ordination across Europe that can help to stop other children going missing in the future.”