A court in Saudi Arabia has sentenced five people to death and jailed three others over the murder of the journalist Jamal Khashoggi last year.

Khashoggi, a prominent critic of the Saudi government, was killed inside the kingdom's consulate in the Turkish city of Istanbul by a team of Saudi agents.

The Saudi authorities said it was the result of a "rogue operation" and put 11 unnamed individuals on trial.

A UN expert said the trial represented "the antithesis of justice".

"Bottom line: the hit-men are guilty, sentenced to death. The masterminds not only walk free. They have barely been touched by the investigation and the trial," Special Rapporteur Agnes Callamard wrote on Twitter.

A report released by Ms Callamard concluded in June that Khashoggi's death was an "extrajudicial execution" for which the Saudi state was responsible, and that there was credible evidence warranting further investigation that high-level officials, including Crown Prince Mohammed bin Salman, were individually liable.

The prince denied any involvement, but in October he said he took "full responsibility as a leader in Saudi Arabia, especially since it was committed by individuals working for the Saudi government".

A senior aide, Saud al-Qahtani, was sacked and investigated over the killing but not charged "due to insufficient evidence", the public prosecution said. Former Deputy Intelligence Chief Ahmad Asiri was put on trial but acquitted on the same grounds.

The Turkish foreign ministry said the decision of the Saudi court "falls short of the expectations of Turkey and the international community for the clarification of all aspects of this murder and the serving of justice".

Khashoggi's fiancée, Hatice Cengiz, called the Saudi announcement "not acceptable".

The publisher of the Washington Post, for whom Khashoggi wrote columns, said: "The complete lack of transparency and the Saudi government's refusal to co-operate with independent investigators suggests that this was merely a sham trial."

But Khashoggi's son Salah, who lives in Saudi Arabia, tweeted: "We affirm our confidence in the Saudi judiciary at all levels, that it has been fair to us and that justice has been achieved."

The shadow cast by the grisly murder of Jamal Khashoggi has hung over Saudi Arabia's international reputation for more than a year now. The ruling princes, especially the all-powerful Crown Prince Mohammed bin Salman, will be hoping Monday's verdicts draw a line under the whole affair. That may be wishful thinking.

The two most senior suspects - dubbed "the masterminds" - have walked free after a trial shrouded in secrecy. The reaction from the UK's foreign secretary has been a carefully-worded call for everyone to be held to account.

Agnes Callamard, the UN special rapporteur who investigated the murder, has been rather more explicit. The trial, she said, was "the antithesis of justice", and "a mockery".

And yet Saudi Arabia, with its vast oil wealth and allies in the White House, will doubtless be expecting that any outrage will soon give way to business as usual.