Nearly five years ago his photo went viral. Little William Tyrrell, then 3-years-old, smiling in his Spiderman costume, was missing.
He disappeared from his foster-grandmother's house in Kendall, New South Wales on September 12, 2014.
Now, almost five years later, an inquest will begin with one person of interest expected to be the focus.
One particular man, who has never been publicly discussed or known to be involved in the investigation, will be the focus of the inquest, according to The Sunday Age.
Despite an intensive police investigation, nobody has ever been charged in relation to William's disappearance.
Over the last four-and-a-half years, investigators have looked into 600 persons of interest, sifted through 15,000 pieces of information and conducted a four-week search of the bushland surrounding William's foster grandmother's home, The Sydney Morning Herald reports.
William's foster parents, his biological mother and representatives from the police and the Department of Family and Community Services are expected to testify during the inquest, beginning in Sydney on March 25.