Police will spend the next four weeks scouring bushland on NSW's mid north coast in a fresh search for clues to find missing Sydney boy William Tyrrell.
Nearly four years after he disappeared, detectives will on Wednesday begin a forensic sweep around the property where he was last seen in Kendall, near Port Macquarie.
William was playing in the yard of his grandmother's home, aged three, when he vanished on September 12, 2014.
Hundreds of locals and emergency services workers spent 10 days looking for him in the rural township, forests, creeks and paddocks.
They thought he was simply lost, and not the possible victim of a crime.
But they found no trace of William.
Detectives have been investigating the circumstances of his disappearance for the past four years, launching a special strike force led by the homicide squad.
The new large-scale search will be co-ordinated by search experts from NSW Police's public order and riot squad.
Lead investigator Detective Chief Inspector Gary Jubelin is due to speak to media at the site on Wednesday.
In 2016, the NSW government announced an unprecedented $1 million for information leading to William's recovery.
Last year, on the third anniversary of his disappearance, his foster family maintained hope of finding him alive.
"William, we will never stop loving you," they said in a statement in September 2017.
"We will never stop looking for you."