Scotland Yard is to begin questioning four formal suspects in the investigation into the disappearance of Madeleine McCann, ITV News understands.
Officers will begin questioning the four people - identified as arguidos, meaning formal suspects - tomorrow at a police station in Faro, Portugal.
Eight key witnesses will also be questioned.
The three-year-old vanished while holidaying with her parents in Praia da Luz in 2007.
More top news
The Duke of Cambridge told crowds he was "delighted" to be back in the Commonwealth country.
When and where are they on, and how do they work?
What better, more dramatic spectacle has there ever been on American television?