Washington (CNN) Two Washington attorneys are calling on International Criminal Court chief prosecutor Fatou Bensouda to push for an investigation into Saudi Arabia's crown prince for the alleged kidnapping, torture and assassination of Saudi journalist Jamal Khashoggi one year after his disappearance as well as for other crimes against humanity, according to a petition obtained by CNN on Tuesday.

Attorneys Bruce Fein, a former associate deputy attorney general under President Ronald Reagan, and W. Bruce DelValle drafted the petition on behalf of the National Interest Foundation, a Washington nonprofit frequently critical of US policy in the Middle East, saying Saudi Crown Prince Mohammed bin Salman "has ruthlessly and systematically persecuted his political detractors, opponents, or rivals," since being elevated to his position in June 2017. The petition was submitted in July but had not been made public

The petition refers to the murder of Khashoggi, who worked for The Washington Post prior to his death on October 2, 2018 ; the torture of dissidents; persecution of human rights activists; multiple war crimes in Yemen and other offenses as instances of the crown prince's crimes against humanity.

Last November, the CIA concluded that bin Salman personally ordered the death of Khashoggi, despite the Saudi government's denials that the de facto ruler was involved. In June, a United Nations investigator said in a report that there is credible evidence the crown prince bears responsibility for Khashoggi's death, though the Saudi foreign minister later called the report "flawed." Although President Donald Trump had signaled that he would not take strong action against Saudi Arabia, a key US ally, or its crown prince, Secretary of State Mike Pompeo said earlier this year that Khashoggi's killers must "be held accountable."

The petition cites cases of states that were not party to the ICC's founding Rome Statute and were still referred by the UN Security Council to the ICC for investigation. Saudi Arabia is not a party to the Rome Statute.

Read More