More than a half-dozen rights and free press groups Friday demanded the U.S., U.K. and France to publicly release assessments of Saudi Arabia's trial of those accused of murdering columnist Jamal Khashoggi.
Riyadh invited representatives from the three countries to attend judicial proceedings, which are otherwise closed to outside observers.
Paris, London and Washington should ensure their presence is not used by Saudi officials to "provide cover for what could be a sham trial," Amnesty International and others said in an open letter.
The Washington Post journalist was killed shortly after he entered the Saudi Consulate in Istanbul last October.
Saudi Arabia initially denied responsibility for the journalist's grisly killing, but later acknowledged he was killed by a team of Saudi operatives it said was conducting a rogue rendition operation.
The narrative, however, has fallen flat for critics who suggest Khashoggi's murder could not have been carried out without the explicit consent of Crown Prince Mohammad bin Salman, the Kingdom's de facto ruler, and suggest Riyadh is seeking to deflect responsibility to fall men.
The closed-door trials "would also run the risk of enabling the authorities in Riyadh to find a set of individuals guilty, without due process, while whitewashing the possible involvement of the highest levels of the Saudi government," the groups wrote to the French, British and American top diplomats.
Other groups making the demand for the disclosure include ARTICLE 19, the Committee to Protect Journalists, Human Rights First, Human Rights Watch, PEN America, and Reporters Without Borders.