Istanbul prosecutors said on Wednesday they had prepared an indictment against a close aide to Saudi Arabia's Crown Prince Mohammed bin Salman and a former deputy head of general intelligence over the killing of journalist Jamal Khashoggi.
The prosecutor's office accused the two men of instigating Khashoggi's murder at the Saudi consulate in Istanbul and named 18 suspects it said actually carried out the killing, which caused a global uproar.
Khashoggi was last seen entering the consulate on Oct. 2, 2018, where he had gone to obtain documents for his impending wedding. Turkish officials said his body was dismembered and removed from the building. His remains have not been found.
The list of 18 suspected killers includes a 15-strong team which flew to Turkey to carry out the operation, and three intelligence officials.
The indictment accuses former deputy head of Saudi Arabia's general intelligence Ahmed al-Asiri and former royal court adviser Saud al-Qahtani of having "instigated premeditated murder with monstrous intent", the prosecutor's office said.
It says the others suffocated Khashoggi, who had grown increasingly critical of Prince Mohammed's actions, after agreeing in advance that he should be killed if he did not return to Saudi Arabia with them.
Saudi Arabia's media ministry did not immediately respond to a request for comment.
Some Western governments, as well as the CIA, have said they believed Prince Mohammed, Saudi Arabia's de facto leader and heir to the throne, ordered the killing - an accusation Saudi officials have denied.
Agnes Callamard, the U.N. investigator who led an international probe into the crime, welcomed the indictment, saying it was needed as a "counter balance to the travesty of justice at the hands of Saudi Arabia".
In a statement to Reuters, she urged U.S. authorities to release their findings on responsibility for the death of the Washington Post columnist, "including the responsibility of Saudi Arabia Crown Prince Mohammed Bin Salman".
Callamard said in a report last June that evidence suggested the crown prince and other senior Saudi officials were liable. On Wednesday, she said that the indictment would shed further light on the murder, "its premeditation and instigation by high-level officials".