The six inmates shared their lunches with the 2 1/2-year-old boy, who apparently had wandered away from home, and played with him while authorities located the boy's parents, said Gary Kershner, a correctional officer who was overseeing the prisoners.

"Me and my inmate crew, we just kind of baby-sat for the next three hours," Mr Kershner said. "They were as much entertained by the child as he was by them."

The boy was on Route 550, not far from the Pennsylvania border, when a lorry driver stopped to pluck him off the road shortly after 9 am.

Mr Kershner, who had stopped his van to help, said the driver handed the boy to him for safekeeping until police arrived.

Police eventually found the boy's home nearby. The child was reunited with his family after child services investigated and found no immediate cause to suspect abuse or neglect.

The boy's father, who works at home, told police he had left his son in the care of an 18-year-old daughter, who then left without notice. State police were conducting their own investigation and would report their findings to Frederick County prosecutors for possible charges, Lt Michael Brady said.