The fiancée of slain journalist Jamal Khashoggi has filed a lawsuit in a US court against Saudi Crown Prince Mohammed bin Salman (MBS) accusing him of ordering the killing.

Hatice Cengiz along with Democracy for the Arab World Now (DAWN), the rights group the Washington Post journalist formed before his death have also sued more than 20 other Saudis. These also include people who have been imprisoned for the killing as well as senior government officials who are close advisers to Prince Mohammed.

"The objective of the murder was clear - to halt Mr Khashoggi's advocacy in the United States... for democratic reform in the Arab world," the lawsuit says.

In the lawsuit, Khashoggi's fiancée claims personal injury and financial losses over his death while DAWN says its operations were hampered, international media reported. “This lawsuit is also a search for the entire truth,” Keith M. Harper, a lawyer for Cengiz said at a news conference.

In 2018, Khashoggi disappeared from the Saudi consulate in Istanbul where he went to obtain papers he needed to marry Cengiz, a Turkish citizen. He was later pronounced dead.

Khashoggi’s body has never been found. In its assessment, the United States Central Intelligence Agency (CIA) concluded that MBS ordered the murder of Khashoggi.

The crown prince has denied ordering the killing.