William, then aged three, went missing from his grandmother's property in Kendall on the NSW mid-North Coast on September 12, 2014.
The toddler was reportedly playing in the yard when he went missing.
At the time of the disappearance, an extensive 10-day search involving police, locals and emergency services was conducted, but William was never found.
NSW Police today said detectives from Strike Force Rosann, formed to investigate William’s disappearance, will begin the forensic search in bushland near the home.
The operation will be co-ordinated by search experts from NSW Police’s public order and riot squad.
Police will provide more details at a press conference on Wednesday morning.
It remains unclear what triggered this latest search.
On the second anniversary of William’s disappearance in 2016, the NSW government announced a $1 million reward for information leading to his recovery.
This is a developing story.
This article originally appeared on New Idea.