AJ Elfalak found
© 7NEWSAnthony “AJ” Elfalak’s family react after finding out he was found alive.
A three-year-old boy who went missing from his family's property in NSW Hunter region has been found.

Anthony "AJ" Elfalak, who has autism and is non-verbal, disappeared from the Putty property before midday on Friday.

More than 130 police officers, volunteers and other authorities spent the weekend searching the property and its surrounding areas.

AJ was found on Monday morning, three days after he went missing.

"Missing three-year-old boy Anthony 'AJ' Elfalak has been located a short time ago," NSW Police said.

"He is yet to be assessed by NSW Ambulance paramedics."

AJ's father Anthony said he felt "amazing" after his son was found.

He added the boy suffered nappy rash, had been bitten by ants and has fallen over.

AJ was found in a creek, drinking water, about half a kilometre from the home.

"We have searched that area head to toe. The first day it happened, I went around with police," Anthony told reporters at the property.

"It's a miracle. He's alive. It's amazing.

"I've been in the bush for four days, I haven't slept."

AJ is "clinging to his mum" and will be taken to hospital for a full checkup, Anthony said.

Family friend Alan Hashem said he felt "incredible" after news AJ had been found.

"But we still need to find out what happened, we need answers," Hashem told 7NEWS.

"How did he leave? Who did he leave with? Did anything sinister happen?

"We will not stop until we find the truth.

"Thank you to every Australian that was praying because miracles do come true."

Another family friend said AJ was found at the bottom of a 15-20m cliff about a kilometre away from the home on the 650-acre property.

The family has been living at the property for just a few months.

AJ was found just hours after Hashem told Sunrise the family believed AJ was abducted.

Alan Hashem said CCTV cameras had been installed to overlook the property but there was a four-hour window where the footage was missing.

"We went in there, and I can't explain it, the window in which he went missing ... probably about four hours, there's footage missing," he said.

Hashem echoed AJ's mother Kelly's theory that the boy had been "taken", adding there was a "suspicious" car seen at the property before AJ disappeared.

"We are absolutely baffled," he said.

"Where your camera is at the moment, if you pointed the complete opposite way you will see how high up the house is.

"The only reasonable explanation is because we are at the front of the house, the father was fixing one of the four ATVs, the mother was cooking in the kitchen and she would overlook the front yard, I was on the side closest to the road where the street is.

"The only part we couldn't see would be the back garage and the back door.

"Unfortunately, that is the same direction we saw a car travel from and head towards the road.

"So, there is no other reasonable explanation than an abduction."

A white dual cab ute was seized for forensic testing over the weekend.