RIYADH: A Saudi court on Monday overturned five death sentences over journalist Jamal Khashoggi's murder in a final ruling that was condemned by his fiancee and slammed by a UN expert as a "parody of justice".

Eight unnamed defendants were handed jail terms of between seven and 20 years in a verdict that comes after Khashoggi's sons "pardoned" the killers in May, paving the way for a less severe punishment.

The court ruling underscores Saudi efforts to draw a line under the October 2018 murder as the kingdom seeks to reboot its international image ahead of November's G20 summit in Riyadh.

"Five of the convicts were given 20 years in prison and another three were jailed for 7-10 years," the official Saudi Press Agency said, citing a spokesman for the public prosecutor.

None of the defendants were named in what was described as the final court ruling on the murder, which triggered an international outcry and tarnished the global reputation of Crown Prince Mohammed bin Salman.

Hatice Cengiz, the Turkish fiancee of the slain journalist, branded the verdict a "farce".

"The ruling handed down today in Saudi Arabia again makes a complete mockery of justice," Cengiz said on Twitter.

Agnes Callamard, the UN special rapporteur on extrajudicial, summary or arbitrary executions, slammed the ruling as "one more act today in this parody of justice". "These verdicts carry no legal or moral legitimacy," Callamard wrote on Twitter. "They came at the end of a process which was neither fair, nor just, or transparent."