UN special rapporteur Agnes Callamard's report, released Wednesday, June 19, insists there is "credible evidence" to warrant further investigation and financial sanctions against Crown Prince Mohammed bin Salman over Khashoggi's murder last October.
The document detailing the dissident's murder by Saudi agents at the country's Istanbul consulate has cast a renewed spotlight on the case just as Saudi Arabia's de facto ruler appeared to be emerging from the scandal.
The revelations, including audio transcripts showing the Saudi agents involved referring to Khashoggi as a "sacrificial animal", have piled pressure on Western allies to suspend arms sales to the kingdom.
Riyadh rejects the allegations, which were likely to spur skepticism for Saudi support in the US Congress despite the prince enjoying President Donald Trump's backing.
"A new crisis cycle is open," Joseph Bahout, non-resident fellow at Carnegie Endowment, said on Twitter.
"Another round of international embarrassment for (Saudi Arabia) is starting now."
On Thursday, US lawmakers voted to block Trump's arms sales worth $8.1 billion to Saudi Arabia shortly after Britain temporarily suspended similar sales.
The decisions were not directly linked to the report, but come after virulent criticism in the US and Britain over the kingdom's four-year bombing campaign in Yemen.
Global revulsion over Khashoggi's murder had shone a spotlight on the Saudi-led war in Yemen, gripped by what the UN calls the world's worst humanitarian crisis.
The UN expert's report is unlikely to challenge Prince Mohammed's position at home, where his grip on power "appears absolute", said Hussein Ibish, a scholar at the Arab Gulf States Institute in Washington.
"The bigger concern, I have no doubt, is the growing anti-Saudi sentiment in US Congress," he told AFP.
"Riyadh's relationship with Washington is not optional from a Saudi point of view. It's essential."
Last month, Trump bypassed the usual process of seeking a congressional green light for the arms sales, citing risks from Iran – a common foe of Riyadh and Washington.
Now the move to block his sales comes as tensions with Iran soar after recent attacks in the Gulf on oil tankers and the shooting down of a US drone. Washington has blamed Tehran for both.
Accusations of a cover-up
While Callamard's report did not offer definitive evidence linking Prince Mohammed to Khashoggi's murder, it said it was "inconceivable" such a large-scale operation could be implemented without him being aware.
The report said there was evidence that the consulate had been "forensically, cleaned" following the killing, indicating a cover up.
Khashoggi's remains have so far not been found.
Saudi Arabia has placed 11 unnamed suspects on trial for the murder.
But the report said the murder involved a 15-man team that flew to Istanbul on two jets in a mission that required "significant government coordination, resources and finances".
The Saudi minister of state for foreign affairs, Adel al-Jubeir, has dismissed the report, saying that it was riddled with "clear contradictions" and "unfounded allegations".
Diplomats from the UN Security Council's permanent members – Britain, China, France, Russia and the United States – as well as Turkey are allowed to attend the trial proceedings of the 11 suspects, Jubeir said.
The proceedings are held entirely in Arabic, diplomatic sources have told AFP, adding that the diplomats are not allowed to bring interpreters.
The incident had tarnished the reputation of Prince Mohammed – a self-styled reformer seeking to modernize the conservative petro-state.
The kingdom had been attempting to turn the page on it, in hopes of winning back foreign investment and resetting ties with Western allies.
The report could "increase the reputational risks for US entities doing business with Saudi Arabia", Ryan Bohl, from the US geopolitical think tank Stratfor, told AFP.
Prince Mohammed also faces overseas critics, including some Saudi citizens who have sought exile in Western capitals.
"This UN report will put winds into their sails and give them an opportunity to build up their public support," Bohl said. – Rappler.com