A Turkish court has opened the trial in absentia of two former aides of Saudi Crown Prince Mohammed bin Salman and 18 other Saudi nationals over the 2018 killing of Washington Post columnist Jamal Khashoggi.

Prosecutors have indicted the 20 Saudi nationals over Mr Khashoggi’s grisly killing at the Saudi Consulate in Istanbul in 2018, which cast a cloud of suspicion over Prince Mohammed.

They are seeking life prison terms for the defendants, who have all left Turkey.

Saudi Arabia rejected Turkish demands for the suspects’ extradition and put some of them on trial in Riyadh.

The proceedings were widely criticised as a “whitewash”, and Mr Khashoggi’s family later announced that they had forgiven his killers.

Turkey Khashoggi Killing
Hatice Cengiz, the fiancee of murdered Saudi journalist Jamal Kashoggi (Emrah Gurel/AP)

The trial in Turkey will be closely watched for possible new information or evidence into the killing, including the whereabouts of Mr Khashoggi’s remains.

The Turkish prosecutors have charged the prince’s former advisers, Saud al-Qahtani and Ahmed al-Asiri, with “instigating a premeditated murder with the intent of (causing) torment through fiendish instinct”.

Prosecutors are also seeking life prison sentences for 18 other Saudi nationals charged with carrying out “a premeditated murder with the intent of (causing) torment through fiendish instincts”.

Mr Khashoggi, who was a resident of the US, had walked into his country’s consulate on October 2 2018 for an appointment to pick up documents that would allow him to get married. He never walked out.

A team of 15 Saudi agents had flown to Turkey to meet Mr Khashoggi inside the consulate.

Turkey Khashoggi Killing
Jamal Khashoggi (Hassan Jamali/AP)

They included a forensic doctor, intelligence and security officers and individuals who worked for the crown prince’s office.

Turkish officials allege Mr Khashoggi was killed and then dismembered with a bone saw.

Turkey, a rival of Saudi Arabia, apparently had the Saudi Consulate bugged and has shared audio of the killing with the CIA, among others.

Prior to his killing, Mr Khashoggi had written critically of the Saudi crown prince in columns for the Washington Post.

Saudi Arabia had initially offered shifting accounts about Mr Khashoggi’s disappearance. As international pressure mounted because of the Turkish leaks, the kingdom eventually settled on the explanation that he was killed by rogue officials in a brawl.

Turkish prosecutors say the suspects “acted in consensus from the beginning in line with the decision of taking the victim back to Saudi Arabia and of killing him if he did not agree”.

Members of the media work outside the court in Istanbul (Emrah Gurel/AP)
Members of the media work outside the court in Istanbul (Emrah Gurel/AP)

Riyadh had insisted that the kingdom’s courts are the correct place for the suspects to be tried, and put 11 people on trial over the killing.

In December, five people were sentenced to death while three others were found guilty of covering up the crime and were sentenced to a combined 24 years in prison.

During the Muslim holy month of Ramadan in May, Mr Khashoggi’s son announced that the family had pardoned the killers, giving a legal reprieve to the five government agents who were sentenced to death.