Kate McCann was next to check on the children, at 10pm. She ran back to the restaurant moments later, saying Madeleine was missing. The McCanns and their friends made a quick search of the resort, but after finding no sign of Madeleine the police were called at 10.14pm.
Crucially, however, the apartment was not initially treated as a crime scene, meaning around 20 people went in and out before it was sealed off, contaminating potential evidence. Roadblocks were not put in place until 10am the next day, border guards were not informed for hours and Interpol did not put out a global missing persons alert for five days.
It meant that the most crucial time of any missing persons investigation – the first 24 hours – was largely squandered
http://www.telegraph.co.uk/news/2016...owing-the-tru/