Jamal Khashoggi's final words were "I can't breathe," CNN said on Sunday, citing a source who has read the transcript of an audio tape of the final moments before the journalist's murder.
The source told the US network the transcript made clear the killing was premeditated and suggests several phone calls were made to give briefings on the progress.
CNN said Turkish officials believe those calls were made to top officials in Riyadh.
Khashoggi, a Saudi contributor to The Washington Post, was killed shortly after entering the kingdom's consulate in Istanbul on October 2.
The transcript of the gruesome recording includes descriptions of Khashoggi struggling against his murderers, CNN said, and references sounds of the dissident journalist's body "being dismembered by a saw."