Khashoggi entered the consulate last Tuesday and has not been heard of or seen since, his fiancée and friends say.
Writer Jamal Khashoggi, who had written critically about Prince Mohammed and the kingdom, vanished October 2 while on a trip to the consulate to get paperwork so he could be married to Cengiz.
The Saudis intend to blame elements within their country's deep state, security establishment for the journalist's kidnapping, the source said.
Turkish officials have said they believe Khashoggi was killed inside the consulate. "If he left the building, then you need to prove it", the Turkish leader said during a joint press conference with Hungarian Prime Minister Victor Orban in Budapest. US officials think it's possible the Crown Prince wanted Khashoggi silenced, but miscalculated the global impact his disappearance would have.The Washington Post first reported the details of the intercepts.US President Donald Trump is facing increased pressure over the Khashoggi case.
"What was explained to us is this: "He was killed, make your funeral preparations", Kislakci said.
He had been living since previous year in the United States, in a self-imposed exile, in part due to the rise of Prince Mohammed, the son of King Salman.
Asked about a Washington Post report that USA intelligence had intercepted top Saudi officials discussing a plan to capture Khashoggi, Trump told Fox, "It would be a very sad thing".
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I think there's something being released on Netflix soon, a documentary based around that fight, and it will have all the rounds. White told "First Take" on Monday that McGregor has also brought it up to him directly. "I am going to regard this severely.
But the disappearance of the journalist, however prominent, may not affect President Trump's bet on the Saudi heir to the throne.
On Monday, Turkish President Recep Tayyip Erdogan said officials from the Saudi consulate in Istanbul must "prove" that Khashoggi made exit from the mission.
Saudi Arabia has insisted the journalist left the building safely.
The recent effort by the Saudi regime to clean up its image has completely been demolished with the disappearance of the Saudi writer. "We are fully aligned with the United States on this, with the USA position on this", she said.
While the Saudis have denied the accusations, an official with Turkey's AK Party told CNN Turk (the Turkish outlet of the American media agency), that there was evidence proving that Riyadh was involved in the alleged assassination. Riyadh's envoy in Ankara was first called to the ministry on Wednesday.
A former editor of the al-Watan newspaper and a short-lived Saudi TV news channel, Mr Khashoggi was for years seen as close to the Saudi royal family.
He has not been heard from since October 2, when he entered a Saudi Arabian consulate in Turkey to receive marriage paperwork.
After three hours of waiting, Cengiz was told that Khashoggi had already left but she says "there's no proof that he came out".