The murder of journalist Jamal Khashoggi was "a brutal and premeditated killing" which was planned by Saudi officials, a UN inquiry has stated.
It comes after the Washington Post correspondent's death inside the Saudi consulate in Istanbul last October.
A further allegation from the inquiry is that Saudi Arabia "seriously undermined" Turkey's efforts to investigate the murder.
Agnes Callamard, the U.N. special rapporteur on extrajudicial, summary or arbitrary executions, made her assessment on Thursday after visiting Turkey.
She plans to present a final report to the UN Human Rights Council in June.
A statement from Ms Callamard said: "Woefully inadequate time and access was granted to Turkish investigators to conduct a professional and effective crime-scene examination and search required by international standards for investigation."
In Saudi Arabia, 11 nationals are facing trial in connection with the killing, though the UN has said it has "major concerns" over the fairness of proceedings against them.
Mr Khashoggi was killed after he entered the Saudi consulate in Istanbul to obtain documents for his wedding.
The journalist's fiancee waited outside the consulate for hours awaiting his return, then raised the alarm when she grew concerned he had not emerged.
Audio tape of his death was reportedly captured by Turkish officials.
Mr Khashoggi was critical of Saudi Arabia in his writing and also of Saudi Crown Prince Mohammed bin Salman.
However, Saudi officials have consistently distanced the royal family from having any involvement in the killing.
