Twenty Saudi nationals have gone on trial in absentia in Turkey over the murder of Saudi journalist Jamal Khashoggi, the BBC reports. Khashoggi was working for the Washington Post at the time of his murder.

Khashoggi was killed in October 2018, at some point after he entered the Saudi consulate in Istanbul in order to obtain necessary documents for his upcoming wedding. His fiancee was waiting outside; Khashoggi never emerged.

Those being tried include two former top aides to Saudi Arabia's powerful Crown Prince Mohammed bin Salman, and the CIA as well as several Western governments believe the murder was ordered by the Crown Prince, which he has denied, and the Saudi regime officially calls the murder a "rogue operation." Khashoggi was an outspoken critic of the prince, who is the de facto ruler of Saudi Arabia.

Turkish prosecutors are accusing the former deputy head of Saudi intelligence, Ahmed al-Asiri, and the royal court's media adviser Saud al-Qahtani of having led the operation and instructed a Saudi hit team. The other 18 defendants are accused of having suffocated Khashoggi, whose remains have not been found. Turkish officials say his body was dismembered and removed to an unknown site.

Last year, a court in Saudi Arabia sentenced five people to death and three to jail for Khashoggi's killing, but the trial was secretive and the defendants were not named; the proceedings were heavily criticized by other countries.