The sources have told Sky News the writer had been “cut up” and his face “disfigured”.
One source also suggested Mr Khashoggi’s remains were discovered in the garden of the Saudi consul general’s home.
it comes after Turkey’s president earlier said Mr Khashoggi’s body had not been found and demanded Saudi officials reveal its whereabouts.
Recep Tayyip Erdogan, who had promised the “naked truth” about the killing, said: “Why has the body of someone who was officially said to be killed not been found yet?”
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There was also no mention of an alleged audio recording that the Turkish authorities claim to have of Mr Khashoggi’s death that supposedly confirms he was tortured, killed, had his fingers cut off and was dismembered.
The Turkish president gave no specific details on how the 59-year-old was killed but said his death was planned days in advance by Saudi officials.
He said Turkish investigators had evidence the Saudi journalist was the victim of a premeditated “savage murder” by a 15-man hit squad.