JACKSONVILLE, Fla. -- A Florida couple have been charged with child neglect after authorities discovered their 17-year-old adopted son, who weighed 49 pounds and was forced to sleep in a cage-like bed.

Child welfare workers in Jacksonville were called to Wilson and Brenda Sullivan's home in January. They say they found the boy wearing a diaper and that he appeared developmentally delayed.

Police Tuesday arrested the adoptive parents on charges of child neglect after a six-week investigation into the treatment of the boy, who officials say was grotesquely underweight.

The investigation into Brenda Sullivan, 48, and Wilson Sullivan, 55, began Jan. 10 after the Department of Children and Families hot line received an anonymous tip.

Jacksonville Sheriff's Office Chief Steve Weintraub said the teen was less than 4 feet 6 inches tall and weighed only 49 pounds and was kept in an enclosed crib "similar to a cage" that had a chain and padlock.

Police said the Sullivans have only told investigators they kept the teen inside the locked crib because he was gorging himself on food at night.

According to the police report, the 17-year-old was height of an average 9½-year-old and weight of an average 6½-year-old. The boy was wearing a diaper when found and appeared to be developmentally delayed.

"This child suffers from the result of psychosocial dwarfism and starvation," the report said.

Police said the Sullivans moved to Florida from Akron, Ohio, last October. The 17-year-old, who had been with the couple for 10 years, and two 10-year-olds were immediately removed from the home.

"We were disgusted and outraged by the condition of the children at that time," John Harrell, spokesman for the child welfare agency, said in statement. "DCF has been working with law enforcement on this tragic case. We are pleased to report that the children are now safe and improving."

The 17-year-old has put on almost 30 pounds since being removed from the home.

The Sullivans are being held under $200,003 bond and are scheduled to face a judge Wednesday. Child neglect is a second-degree felony that can carry a prison sentence of up to 15 years.