Adoptive Parents Arrested for Allegedly Keeping 55-Pound Teen Son Locked in Basement

(INSIDE EDITION) An Alabama teen is fighting for his life after his adoptive parents allegedly locked him in a basement with little food, water or medical supplies during long periods of time for nearly two years, authorities said.

The unidentified 14-year-old boy allegedly weighed only about 55 pounds -- less than half of what the average boy his age should weigh -- when Richard and Cynthia Kelly brought him to the hospital after his condition worsened, according to reports.

Through the Shelby County Department of Human Resources, that hospital's staff notified Helena police of the alleged abuse and an investigation was launched Sunday.

Read: Woman Abused Boyfriend's Child Because He Wasn't Hers and Had 'Stupid Ugly Face': Cops

The couple allegedly denied food, nourishment and medical care to the boy, who was "subjected to forced isolation for extended periods of time" as a disciplinary tactic, according to arrest warrants obtained by AL.com.

"It's the worst case of neglect that I have ever seen," Helena Police Chief Pete Folmar said.

The Kellys were charged Monday with aggravated child abuse and are being held on $1 million bond each.

They had another adopted child living with them, but that subject is now a legal adult and was in good condition, officials said.

Read: Mom Investigated After Viral Video Shows Her 'Kicking Son Out' Over 'Voting' for Trump

The victim, whose name has not been released, is in critical condition at an undisclosed hospital, authorities said.

"The victim continues to get medical care and we at the Helena Police Department wish him a speedy recovery and our prayers are with him," police said in a statement.

Officials noted that the boy's case is one of the most horrific to have ever been investigated in the area.

"I am bound to remind everyone that they remain innocent until proven guilty," Shelby County District Attorney Jill Lee told AL.com. "But this office will prosecute vigorously and to the fullest extent the law will allow."