Justice 'trampled' in Khashoggi murder trial: media watchdog RSF
The group's secretary general, Christophe Deloire, tweeted that the sentences "can be interpreted as a means to permanently silence the suspects, a way to prevent them from speaking to better cover up the truth."
The trial, which had taken place behind closed doors, "did not respect international standards of justice," he said, adding: "Justice has been trampled on."
"The opacity of the procedure and the concealment of evidence does not allow us to get an idea" of why several others were convicted or acquitted, said Deloire, insisting: "We still expect a full accounting."
Khashoggi, a Washington Post contributor, was murdered in October last year in what Riyadh called a "rogue" operation, tipping the kingdom into one of its worst diplomatic crises and tarnishing the reputation of Crown Prince Mohammed bin Salman.
The 59-year-old Saudi insider-turned-critic was strangled and his body cut into pieces by a 15-man Saudi squad inside the kingdom's consulate in Istanbul, according to Turkish officials.
On Monday, a court in Riyadh sentenced five of the 11 unnamed individuals indicted in the case to death and three to 24-year jail terms, while it acquitted the rest.
"The court issued death sentences on five men who directly took part in the killing," the prosecutor said in a statement.
"We found that Khashoggi's murder was not premeditated," Saudi deputy general prosecutor Shalaan al-Shalaan told a press conference.
Two senior aides to Saudi Arabia Crown Prince Mohammed bin Salman have been exonerated of the crime, the court ruled.
No evidence was reportedly found against Saud al-Qahtani, who was removed from his role as a top adviser to the crown prince in the aftermath of the murder, according to Shalaan Shalaan, the deputy attorney general.
Dubbed the "Saudi Steve Bannon", Qahtani was a brutal media enforcer for Mohammed bin Salman, masterminding the arrest of hundreds of the country's elite and orchestrating the detention of Lebanese Prime Minister Saad Hariri.
He was a royal adviser to Mohamed bin Salman until he was sacked in October, a move that was widely seen as an attempt to scapegoat Saudi officials and cover up Prince Mohammed's likely role in the murder of journalist Jamal Khashoggi.
According to intelligence sources, Qahtani ran the brutal killing of Khashoggi at the Saudi consulate via Skype.
A Turkish intelligence source said in October that Qahtani told his men to dispose of Khashoggi. "Bring me the head of the dog", the Turkish intelligence source says Qahtani instructed.
Around 11 messages were sent between Qahtani and the crown prince roughly at the time of the journalist's brutal murder, according to the CIA.
Earlier this year, a Turkish prosecutor demanded that arrest warrants be issued for Qahtani and Ahmad al-Assiri, who he described as being "among the planners" of Khashoggi's murder.
But the court on Monday found Alassiri, a top intelligence official who was also removed from his position, not guilty.
Khashoggi was a longtime royal court insider and editor at state-linked newspapers in Saudi Arabia who described himself as worried by the rise of Crown Prince Mohammed bin Salman. He had criticised the prince in his last job as a Washington Post columnist.
His dismembered body has not been found.
Saudi Arabia initially offered multiple shifting accounts about Khashoggi's disappearance. As international pressure mounted, the kingdom eventually settled on the explanation that he was killed by rogue officials in a brawl inside the consulate.