The fiancee of Saudi journalist Jamal Khashoggi has said Saudi authorities are responsible for his murder, and the kingdom should give more details so that those who ordered and carried out the killing can be brought to justice.

The death of Khashoggi — a Washington Post columnist and a critic of Saudi Arabia's de facto ruler, Crown Prince Mohammed bin Salman — sparked global outrage and pitched the world's top oil exporter into crisis.

When asked who was ultimately responsible for the killing, his fiancee, Hatice Cengiz, told Reuters in Turkish: "This took place inside a Saudi diplomatic mission. ... In such circumstances, the Saudi Arabian authorities are responsible for this.