"There are a lot of indications, but without more elements it's impossible to determine what happened" the night Madeleine, then 3, disappeared May 3 during a family vacation in Praia da Luz, a high-ranking Portuguese police official told the 24 Horas newspaper.
The lack of evidence appears to have made Portuguese police step back from charging Madeleine's parents, Gerry and Kate McCann, with her disappearance, London's Telegraph reported Saturday.
The McCanns, both 39-year-old doctors from Rothley, England, have been declared formal suspects. They spent Friday in London consulting with their lawyers as reports emerged that Portuguese detectives want to re-interview some of the friends they dined with May 3, The Telegraph said.
The McCanns have said they are innocent but feel frightened and "backed into a corner" by the investigation, The Telegraph reported.