In the 10 years since Madeleine McCann disappeared from a holiday apartment in Portugal, myriad theories about what happened to her have taken root, but only one fact remains uncontested: that she was reported missing at 10.14pm on the evening of Thursday, May 3, 2007.

It was at that point, when police were called, that the clock started ticking on the biggest missing persons investigation for decades, a search that remains very much active to this day.

Facts, the hard currency of any police investigation, have proved almost uniquely elusive; every sighting, every timing and every witness statement has been disputed in the years that have elapsed since.

Madeleine’s parents Kate and Gerry McCann quickly came under suspicion by Portuguese police, a development that the couple are certain meant vital clues were missed in the first hours and days after Madeleine’s disappearance.

Every possible theory has been explored since then: that Madeleine was abducted by a paedophile; that she was killed during a bungled burglary and her body dumped; that she was abducted by traffickers and sold to a childless couple; that she wandered out of the apartment and died in a tragic accident, and many more besides.

To date, however, not one shred of proof of what happened to Madeleine has been unearthed. That question would become not only a personal tragedy for the McCann family, but a national obsession in the UK and in Portugal.