NEW YORK (AP) — A third person has been charged in the death of a toddler apparently poisoned by fentanyl inside a New York City day care center, authorities said as the search continued for the alleged ringleader of the drug peddling operation.

Renny Antonio Parra Paredes, 38, was charged with narcotics distribution resulting in death on Monday, ten days after authorities discovered four young children showing signs of opioid exposure at a Bronx day care center. One of those children, 1-year-old Nicholas Dominci, was pronounced dead last Friday.

Federal prosecutors said Paredes, who also went by “El Gallo,” played an “instrumental role” in selling large quantities of fentanyl and other drugs that were packaged and stored inside the day care facility – including on mats used by children for sleeping.

“Today’s arrest is one more step toward obtaining justice for the child-victims of this heinous offense and their families,” Manhattan US Attorney Damien Williams said in a statement.

The operator of the day care centre, Grei Mendez, and a tenant of the apartment, Carlisto Acevedeo Brito, were charged with murder of “depraved indifference” last week. Both were ordered held without bail.

Police continued to search for Mendez’s husband, who was seen leaving the Bronx apartment carrying two full shopping bags minutes after Mendez warned him about the unresponsive children.

At a court hearing last week, an attorney for Mendez said his client had panicked after finding the children in her care were not waking up from their naps, but argued that the drug dealing allegations were “about Ms Mendez’s husband, not her.”

A search of the Bronx day care center revealed a kilogram of fentanyl atop kids’ play mats in a closet and a stash of drug paraphernalia hidden inside the floor where children played, including glassine envelopes bearing a “Red Dawn” stamp, according to court documents.

That same stamp was allegedly found in the apartment where Paredes was staying, along with a cache of other drug supplies, the court filings indicated.

Cell phone location data suggested Paredes made regular stops at the Bronx day care centre, while text messages show a phone number labelled “El Gallo” in regular communication with Brito about the operation, according to the filings.

In one message sent to Brito, “El Gallo” allegedly warned that if Mendez’s husband was “going to take the garbage out, the police are out there on the side.” In another, “El Gallo” says he’s left Brito “una torta,” a Spanish word that investigators said is used to refer to a kilogram of narcotics

Paredes is expected to appear in federal court on Monday.