In the ongoing investigation into One Direction singer Liam Payne’s death, three suspects have been charged for their alleged involvement in the pop star’s sudden demise last month.

The National Criminal and Correctional Prosecutor’s Office of Argentina announced Thursday in a statement shared in Spanish that it has found evidence of “illicit conduct” by three people — including an employee of the hotel where Payne fell to his death. Charges included abandonment of a person followed by death, and supply and facilitation of narcotics. The suspects, who were not identified, were charged last Friday in a 180-page indictment delivered to judge Laura Graciela Bruniard, the statement said.

Payne, an “X Factor” alum who also pursued a solo musical career after his One Direction days, died Oct. 16 after falling from a third-floor balcony at a hotel in Buenos Aires. He was 31.

In a preliminary autopsy shared a day after the singer’s death, Argentine officials said authorities found substances in the singer’s room that appeared to be drugs in addition to evidence of consumption of alcohol and narcotics.

Officials carried out nine raids and heard “several dozen” testimonies from people including hotel staff, Payne’s family and friends, medical professionals and other experts, Thursday’s announcement said. Police analysts also reviewed more than 800 hours’ worth of surveillance footage from in and around the hotel, combed through the contents of Payne’s phone (including calls and messages across various messaging and social media apps) and assessed the registry of guests and the singer’s orders from the hotel’s bar and restaurant to understand his drinking and eating habits.

Officers from the Cybercrime unit also extracted information from the cellphones of hotel reception and volunteer witnesses to corroborate statements.

Prosecutors allege that one of the defendants accompanied Payne on a daily basis during his stay in Buenos Aires. Payne died two weeks after he arrived in Argentina, where he attended an Oct. 2 concert by former One Direction bandmate Niall Horan. This defendant was charged with abandonment of a person followed by death, and supply and facilitation of narcotics, the statement said. The remaining two defendants were charged with supplying narcotics.

One defendant is a hotel employee who allegedly provided Payne with cocaine during his stay. The other is a suspected narcotics supplier who had already been accused of dealing drugs in separate incidents, Thursday’s statement said.

The investigation into Payne’s death is ongoing and the prosecution said it was considering ruling out the possibility of suicide, because “in the state [Payne] was going through, he did not know what he was doing nor could he understand it.”

In October, officials determined Payne died from multiple traumas and internal and external bleeding caused by the fall. He “did not adopt a reflexive posture to protect himself and … he may have fallen in a state of semi- or total unconsciousness,” officials said last month.

Payne had traces of alcohol, cocaine and a prescription antidepressant in his system in the moments before his death, Thursday’s statement said. Prosecutors confirmed that Payne’s body had been delivered to his father, Geoff Payne.

Payne’s remains reportedly will be flown back to his native London, one of the cities where One Direction fans gathered last month to celebrate the singer’s life and music.

Payne’s track “Do No Wrong” was set for a posthumous release last week, but plans were swiftly put on hold after fans pushed back.

“Today I’m deciding to hold ‘Do No Wrong’ and leave those liberties up to all family members,” Payne’s collaborator Sam Pounds said last week in a since-deleted tweet. “I want all proceeds [to] go to a charity of their choosing (or however they desire).”

Pounds added: “We are all still mourning the passing of Liam and I want the family to [mourn] in peace and in prayer. We will all wait.”

Times staff writer Nardine Saad contributed to this report.