'It's torture': Dad speaks out amid desperate search for missing 6-year-old Maddox Ritch

The father of Maddox Ritch says the desperate search for his 6-year-old son is "torture," days after the boy vanished in a North Carolina park.

Maddox, who has autism and does not talk, went missing Saturday while at the Rankin Lake Park in Gastonia with his father, Ian Ritch, and an unidentified adult, police said.

Maddox was roughly 25 to 30 feet ahead of his father when the young boy started sprinting, Ritch said at a news conference Wednesday.

"I feel guilt for letting him get so far ahead of me," Ritch told reporters. Ritch said he has diabetes and neuropathy in his feet which can cause problems running.

"As soon as I got to the point where I couldn’t see him anymore, I started panicking," Ritch told "Good Morning America" Wednesday.

This was their first time at Rankin Lake Park, Ritch said.

"We searched everywhere," a park employee can be heard saying in a 911 call released by police Wednesday.

"I'm not eating, not sleeping," Ritch told reporters Wednesday.

"I want to give him a big hug," he continued. "It's torture. I just want my little boy back home."

His mother, Carrie Ritch, joined police at a press conference Tuesday.

"Maddox is my whole world and my reason for living," Carrie Ritch said during the press conference.

"If you were at the park Saturday and saw Maddox ... please, urgently, please call the tip line," she said through tears. "I want my baby back in my arms."

Investigators have checked dozens of dumpsters, searched the park's lake using sonar and divers and scanned the area with helicopters and drones, police said.

Authorities have also recorded messages from Maddox's parents and are playing those messages in the woods in the hopes that their voices will persuade him to come out if he's there, the FBI said.

Anyone who was at Rankin Lake Park on Saturday is asked to call the tip line at 704-869-1075. A $10,000 reward is being offered.

"We have spoken to many people who were there, but we want to make sure we talk to them all," Gastonia Police Chief Robert Helton said in a statement released by police Monday. "No piece of information is too small. Something you may think is insignificant could be helpful to our case."

Maddox has blond hair and blue eyes, weighs 45 pounds and is 4 feet tall, police said. He was wearing black shorts, closed-toe sandals and an orange T-shirt that reads "I am the Man" at the time he went missing, according to police.

A candlelight vigil will be held Wednesday night.