Avonte Oquendo, the 14-year-old mute autistic boy from New York City, is still missing after police mistakenly announced that they found the boy Tuesday.

Avonte, who is supposed to be under constant supervision at school, was last seen Friday afternoon walking out of the Center Boulevard School in the Long Island City section of Queens without an aid. Police have searched everywhere from neighborhood streets to subway tunnels in hopes of finding the 14-year-old.

"He cannot communicate at all," worried brother Daniel Oquendo, Jr., told NBC New York. "He can't tell someone if he is hungry, if he is lost. He can't say his name."

Police initially said Tuesday that they found Avonte in East Harlem, but the sighting proved to be false.

“It’s been a roller coaster, a bad roller coaster but we’re still staying positive,” Daniel Oquendo told CBS New York. “It hurts because you do want things to end, but somebody’s child was found, just not ours. But we’ll continue to pray and look.”

Avonte’s mother, Vanessa Fontaine, said she is on pins and needles stressing about Avonte’s fate.

"I just need to find my son because he needs his family, he cannot fend for himself out there," she told ABC New York. "This is just the hardest thing to have your child disappear, and you cannot bring him home with you.”

Surveillance video at Avonte’s school showed him walking out without supervision.

"He is supposed to have one-to-one supervision at all times," Fontaine said. "He has the mental capacity of a 7- or 8-year-old."

Police have scoured train yards and subway tunnels in their search for Avonte because trains are one of his passions, New York City Police Commissioner Ray Kelly said.

“This young man apparently had a fascination with trains, so we’re going forward on that,” Kelly told CBS New York.

A law firm is offering a $5,000 reward for the safe return of the 14-year-old autistic boy, the advocacy group Autism Speaks posted on its website. The organization said Avonte is not verbal and has the mental capacity of a 7-year-old child.

The reward is being doled out by Mayerson & Associates. The firm’s founder, Gary Mayerson, is a member of Autism Speaks’ board of directors.

“We cannot begin to imagine what Avonte’s family is going through.   Time is of the essence.  Our firm is offering a $5,000 reward to the individual who is credited for being directly responsible for locating Avonte and for his safe return to his parents,” Mayerson said.

Anyone with information on Avonte’s whereabouts was urged to contact Mayerson at 212-265-7200.