The inquest into the disappearance of William Tyrrell is set to begin today in Sydney almost five years after he went missing.
The NSW coroner will examine the toddler's family situation and the initial response to his disappearance.
William vanished from his foster grandmother's home on the NSW mid north coast on September 12 2014 while wearing a now infamous Spiderman costume.
Police have worked tirelessly to track down the missing child but there has been no trace of him.