Saudi Arabia says its investigation of the killing of Jamal Khashoggi has cleared Mohammed bin Salman.
The phone conversation, if confirmed, would support Turkey’s assertion that the killing was premeditated.
A Saudi intelligence agent called the farm’s owner a day before the journalist was killed, a Turkish official said.
Several of the activists were also subjected to sleep deprivation, said people familiar with the incidents.
Trump administration imposes sanctions on 17 Saudis after kingdom announces the indictment of 11 citizens in the crime.
The public prosecutor indicted 11 people in the killing but said there are no links to the powerful crown prince.
A Turkish official said investigators believe Saudi Arabia sent a “cleanup” team to cover up the killing.
International furor over Khashoggi killing may be turning up pressure to release some detainees.
Months before Jamal Khashoggi’s disappearance, a Saudi sheikh was allegedly captured in Jordan and repatriated.
American evangelical pastor Andrew Brunson's detention has become a flash point in the rapidly worsening relationship between the United States and Turkey.