The father of a 3-year-old boy in New Jersey was charged after the baby tested positive for methadone, prosecutors said Tuesday.

Roberto Delgado-Gonzalez, 44, of Guttenberg, was taken into custody on Monday evening and was charged with endangering the welfare of a child, a second-degree crime.

According to a statement from the Hudson County Prosecutor's Office, just before 10 a.m. EDT on Monday, officers from the Guttenberg Police Department arrived at an apartment and found the boy unresponsive. They immediately alerted the Hudson County Prosecutor's Office Special Victims Unit.

The unidentified child was first taken to Palisades Medical Center in North Bergen and was later transported to Hackensack University Medical Center, where he was listed in stable condition, the statement added.

The New Jersey Division of Child Protection and Permanency informed detectives that the child's blood toxicology test, which was performed to detect traces of drugs in a person's blood, was positive for methadone. Deputies then arrested his father.

Delgado-Gonzalez was working at the League of Extraordinary Children, a daycare facility in the town, as a teacher, the statement noted.

Methadone, sold under the brand names Dolophine and Methadose, is an opioid drug used to treat drug addiction and also for pain relief.

In April, the parents of a 2-year-old Colorado girl were arrested after the child died due to fentanyl overdose. Officers recovered drugs, including heroin, marijuana and Xanax, in a trash can in the girl's room, which she was sharing with her other siblings. The child's father said he kept the drugs in a lunchbox on a high shelf, out of the children's reach, and that he hadn't seen the child ingest the drug. The girl's death was ruled an accidental fentanyl overdose. A toxicology report indicated the amount of fentanyl found in her blood was three times the fatal level.

Orange County Deputy Probation Officer Erin Merritt holds a canister of methadone
Orange County Deputy Probation Officer Erin Merritt holds a canister of methadone REUTERS/Lucy Nicholson