Expert reports are being carried out on phones and computers. And a police special investigations unit raided the hotel on 24 October on the orders of the prosecutors' office and seized items including hard drives and footage from hotel cameras, AP reported.

The full toxicology report must also be completed.

Payne's father Geoff visited the Argentine capital after the singer's death and has "stated to the prosecutor his willingness to testify about everything he knows about his son's life that could help the investigation", the office said.