ISTANBUL — The fiancée of slain Saudi journalist Jamal Khashoggi remains hopeful investigations into his murder will bring his killers to justice. But Hatice Cengiz will have to keep waiting after the US administration refused to issue its findings last week on his death at the Saudi Consulate in Istanbul.

Cengiz, a 37-year-old Turkish doctoral student, was one of the last people to see Khashoggi alive on Oct. 2, 2018, when he entered the consulate to obtain paperwork for their wedding. She recounts that fateful day in a new book, “Jamal Khashoggi: Behind the Murder of the Century,” which is based on her contemporaneous diary and interviews she gave two Turkish journalists.

“Punishing those who carried out Jamal’s murder and prosecuting those who are responsible will relieve some of the heartache,” Cengiz said at the memoir’s launch last week. “The main reason I’ve sought to keep this issue on the public’s agenda is because of the importance of giving his loved ones a grave for his body at which they can pray.”

Khashoggi’s remains were never recovered, and Turkey has said it believes Saudi officials dismembered his body before disposing of it. Turkish leaks of the grisly details of the killing helped spark an international backlash against Saudi Arabia over the murder of the Washington Post columnist, an outspoken critic of Crown Prince Mohammed bin Salman.