They say after the journalist entered the Saudi Consulate in Turkey, a fist fight broke out that allegedly resulted in his death.
Mohamed bin Saleh al Rumeh, assistant to the president of general intelligence for intelligence affairs, Abduallah bin Khalifa al Shaya, assistant to the president of general intelligence for human resources, and Rachad bin Hamed al Muhamadi, director of the general department for security and protection in the command of general intelligence, were also dismissed.
A Saudi foreign ministry official says the kingdom is investigating the "regrettable and painful incident of Jamal Khashoggi's death" and forming a committee to hold those responsible accountable.
The case of Jamal Khashoggi, a man who was once close to the royal Saudi family before a falling out and a self-imposed exile to the USA, has gripped the world's attention over the past few days since his disappearance on October 2.
However, the sources said Ankara is extremely concerned that the suspects will be arrested and executed by Saudi authorities before Turkish investigators can have the opportunity to question them.
Two days after Khashoggi's disappearance, Saudi Crown Prince Mohammed bin Salman told Bloomberg News that the journalist had left the consulate. These Turkish sources said an audio recording existed, though none has been made public or provided to USA authorities.
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When asked if sanctions on Saudi Arabia are possible, Trump said they "could be, could be".
Middle Eastern allies closed ranks around the kingdom after the Saudi statement.
"After the recognition of Khashoggi's death, we expect a determined, constant and powerful pressure to be kept on Saudi Arabia in order to get the whole truth on the case and the release of Saudi Arabian journalists (who have) been condemned to insane and terrible sentences", he added. Turkish media quote officials as saying Khashoggi has been killed and dismembered inside the consulate.
He added that discussions with Khashoggi in the consulate "did not go as required and developed in a negative way, leading to a fight" that in turn led to the journalist's death "and to their attempt to hide and cover what happened".
On Twitter, where al-Qahtani had launched vitriolic attacks against those he saw as the kingdom's enemies, thanked the Saudi government for the "great opportunity they gave me to serve my country all those years".
But he said that, before he decided what to do next, he wanted to talk to Saudi Crown Prince Mohammed bin Salman.
'I will remain a faithful servant of my country for a long time, and our dear homeland will remain lofty, God willing'.
Khashoggi went missing on October 2 after entering the Saudi consulate in Istanbul to obtain documents needed for his upcoming marriage.
He added: "I'm doing what I'm doing as vice chairman of the Conservative party and I don't have time for any other responsibility".