The child who died in a "tragic accident" at Piha on Saturday was found on rocks, a witness said.
The woman, who wanted to be known only as Kelsey-Ann, said she and her partner joined in the search for the 5-year-old boy when they arrived at the beach and a lifeguard approached them.
"When we turned up at the beach a lifeguard came over to us and asked us if we had seen a little boy wearing a yellow top."
She and her partner "had a little look around", and were approached by numerous other people asking if they had seen the boy.
About an hour or two later, Kelsey-Ann's partner asked a lifeguard if there was anything more they could do to help.
"That's when we found out," she said.
She could see the boy's body on the rocks from a distance at North Piha, and said it looked like he might have fallen.
Kelsey-Ann had seen a woman on the beach during the search who she believed to be the boy's mother.
"She just looked devastated, had her head in her hands."
Kelsey-Ann said she felt "horrible" when they discovered what happened to the boy.
"I'm an early childhood teacher, it really hit home. I felt so sorry for his parents, it must feel horrible, I can't imagine it.
Police are yet to release the child's name, as they are still informing family of the death. They have confirmed the child did not drown.