Around the time Khashoggi entered the consulate, a second private plane from Riyadh took off for Istanbul.
Khashoggi, 59, went missing last week after visiting the Saudi consulate in Turkish capital Istanbul to collect paperwork to marry his Turkish fiancee.
Khashoggi, a prominent Saudi journalist, vanished October 2 after entering the Saudi consulate in Istanbul.
"Although my hope slowly fades away each passing day", Cengiz writes, "I remain confident that Jamal is still alive".
"It is like 'Pulp Fiction, '" the official commented.More news: Melania Trump on #MeToo: Accusers Need to Show Evidence of Assault
Robert Pear, a former U.S. ambassador to Turkey, said the case could change the relationship between the United States and Saudi Arabia.
President Trump has said he'll talk to Saudi Arabian officials about the missing journalist at some point.
Erdogan said the prosecutor's investigation into the disappearance of Jamal Khashoggi was continuing.
Further reports said that a group of 15 Saudis entered the consulate on the same day as Khashoggi and soon left the country, and that Khashoggi had been dismembered and smuggled out of Turkey in small boxes.
The Washington Post released on Tuesday what appears to be the last-known photograph of Khashoggi, walking into the Saudi consulate from which he apparently never left.
The Post, citing anonymous USA officials familiar with the intelligence, said Saudi Crown Prince Mohammed bin Salman ordered an operation to lure Khashoggi from his home in Virginia to Saudi Arabia and then detain him.
Although Khashoggi was planning to move to Istanbul, he was also a legal resident of the United States and a contributing columnist for The Washington Post.
The official said that a security delegation consisting of Saudi investigators arrived in Istanbul on Saturday to participate in the investigations into the disappearance of Khashoggi.More news: U.S. Stocks Fall Sharply, Tech Sector Leads Declines
"When President Trump became president, we've changed our armament strategy again for the next 10 years to put more than 60% with the United States of America", he added.
He is also a former editor of the Saudi newspaper al-Watan and had worked with Prince Alwaleed bin Talal, a grandson of the first Saudi king who was detained past year as part of what the authorities said was an anti-corruption campaign.
But what about the US alliance with Saudi Arabia?
Two months later, writing about the detentions of scores of Saudi royals, senior officials and businessmen accused of corruption, he said Mohammed bin Salman dispensed "selective justice" and said there was "complete intolerance for even mild criticism" of the crown prince.
He has written multiple columns recently in The Washington Post where he criticized Crown Prince Mohammed bin Salman.
Erdogan, who said he was personally following the case, added that Turkey had no documents or evidence regarding the case.
A former Saudi government advisor, Khashoggi has been openly critical of Prince Mohammed, accusing him of introducing a new era of "fear, intimidation, arrests and public shaming".More news: Extensive devastation after Hurricane Michael blasts Florida Panhandle