PEOPLE magazine reports: It's likely Liam Payne was using substances in the time leading up to his death.

A source in the prosecutor’s office with knowledge of the investigation, who requested to remain confidential because of the sensitivity of his position, tells PEOPLE that prosecutors believe the drugs were procured for Payne by a hotel employee before the former One Direction member fell multiple stories at the CasaSur Palermo Hotel in Buenos Aires, Argentina, and died at age 31 on Oct. 16.

"There appears to be evidence that a hotel employee sourced the drugs for Payne," the source says. "An indictment for drugs distribution could follow shortly."