After failing to locate the six-year-old autistic boy who went missing in Rankin Lake Park in Gastonia, North Carolina on Saturday, authorities decided to use alternative methods to try and lure out the child. In this photo, members of the Evidence Response Team from the Federal Bureau of Investigation examine a car that allegedly belonged to Syed Farook in Redlands, California, Dec. 3, 2015. Getty Images/ Justin Sullivan

After failing to locate a six-year-old autistic boy who went missing in Rankin Lake Park in Gastonia, North Carolina on Saturday, authorities decided to use alternative methods to try and lure out the child.

The FBI and the local police’s search for Maddox Scott Ritch was complicated from the start since he was non-verbal and hence incapable of calling out for help. So, on Monday, the authorities tried out a different way to reach out to the missing child. They played his parents' voices over loudspeakers around the area where Ritch had disappeared with the hopes that if he was not being held against his will or severely hurt, he would follow the sound and come back to safety.

"We have followed more than 150 leads, conducted hundreds of interviews, gathered surveillance video from stores all over the area. Searched thousands of acres of land on foot, with ATVs and by boat. But we haven't found Maddox," said Gastonia Police Chief Robert Helton, Tuesday, CBS News reported.

FBI supervisory special agent Jason Kaplan said: "If he's lost in the woods, he'll be able to hear those messages played, and we're hoping that he'll come to the words of his mother and his father."

Authorities said they were leaving no stones unturned to find Ritch. Hundreds of investigators, analysts from more than a dozen local, state and federal agencies had joined in the mission to find the missing boy.

Their efforts included expanding their search to two miles beyond the 250-acre park's boundaries. They were also scanning a landfill just a few miles away from the park.

Helton added water from the 80-acre lake inside the park was being drained in order to expose more of the shoreline for examination. They were also contacting local businesses and residential houses for any possible surveillance footage that can help in the case.

"We want to make sure that we're checking every possible spot to find this child," he said, CNN reported.

The FBI announced a $10,000 reward for information in the case.

"I would appreciate it if you were at the park Saturday and saw Maddox, to please, urgently, please, call the tip line, please," Carrie Ritch, the missing child’s mother said in a press conference Tuesday. "Continue praying for him because I just want my baby home, please. Whatever you can do."

Ian Ritch, Maddox’s father, said he could not stop blaming himself for his son’s disappearance.

“These past few days have been hell for me. I’m so broken. I’m heartbroken,” Ian told People Magazine. “Every time it gets dark at night I burst into tears because I’m thinking, ‘My little boy is out there alone.’ The longer [the search is] going the harder it gets because I’m so worried. He hasn’t had anything to eat or drink.”

“People are making it out like I did something to him. I would never hurt my little boy. I love him to death and I just want him back. I’ve been feeling the blame since this happened. I just wish I would have caught him before he got too far away from me. It’s broken my heart to think that I just let him get too far away,” he added.

Maddox was accompanied by his father and another adult at the park around 1:30 p.m. EDT before he went missing.

"They were walking around the lake," Rachel Bagley, Gastonia spokeswoman, said Saturday. "They got around to the back side of the lake. He started running, according to the parents, and when they started running after him, they lost sight of him, and no one has seen him ever since.

Ian said his son never usually ran away on his own but last time was different.

“Usually when he takes off running he’ll slow down and stop for me to catch up with him. This time he never stopped,” he said.

Maddox is four-feet tall, weighed 45 pounds and has blond hair and blue eyes. He was last seen wearing an orange t-shirt with the writing "I am the man" and black shorts with a white stripe. Anyone with any information about Mitch’s whereabouts can call 704-869-1075.