More than 130 people on Sunday continued to look for Anthony "AJ" Elfalak who has autism and is non-verbal.

He went missing about 11.45am on Friday from his family's 260-hectare farm at Putty, near Singleton and search efforts have continued since.

"Searchers hit the ground this morning with over 130 actively searching this large property," Superintendent Tracy Chapman told ABC TV.

"Detectives assisted by specialist resources have formed (a) task force ... to investigate the circumstances surrounding the missing three-year-old."

AJ's relatives fear he may have been taken from the property, family friend Alan Hashem wrote in a Facebook post, appealing for community members to keep any eye out for the child.

"No words other than, 'broken', we will not stop, until we find this precious boy, AJ Elfalak," he wrote on Saturday night.

NSW police have issued a geo-targeted message asking people in the area to look out for the child.

Volunteers are assisting police on foot and on dirt bikes.

Divers also searched and drained a large dam on the property.

AJ is believed to be wearing a grey jumper and pants, as well as sneakers, and is described as being of Mediterranean or Middle Eastern appearance, with short, dark hair.

Anyone with information is urged to contact Crime Stoppers.

Australian Associated Press