Eighteen suspects in the killing of Jamal Khashoggi are accused of murder with "monstrous intent," Turkey's justice ministry said.
The latest update comes after the journalist's fiancee, Hatice Cengiz, spoke of "a darkness I cannot express" in her first interview since his murder.
She told Turkish channel Haberturk: "I demand that all those involved in this savagery from the highest to the lowest levels are punished and brought to justice."
Istanbul prosecutor's office has prepared a request for the extradition from Saudi Arabia of the 18 suspects.
It also said they were accused of murder by "premeditation, monstrous intent or by torture".
On Thursday, Saudi prosecutors said Mr Khashoggi's murder was premeditated, citing Turkish evidence and changing the country's account again to try to ease international outrage.
Turkey will eventually reveal other "information and evidence" about the writer's killing, the country's president Recep Tayyip Erdogan said.
Mr Erdogan added that the Saudi officials who killed the journalist in their Istanbul consulate must reveal the location of his body as he sharply criticised the kingdom's handling of the case.
"It is clear that he has been killed but where is it? You have to show the body," he said during an address to Turkey's ruling party leaders.
He added that Saudi Arabia's chief prosecutor will arrive in Turkey on Sunday as part of the investigation and will meet Turkish counterparts.
Key mysteries including whether the murder was carried out with the knowledge of Crown Prince Mohammed bin Salman, who denies it, and the location of Mr Khashoggi's body remain.
Mr Erdogan criticised initial Saudi statements that claimed the journalist had left the consulate unharmed after going there for paperwork related to his planned marriage to Ms Cengiz.
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"He will leave the consulate and not take his fiancee with him? Such childish statements do not go hand in hand with statesmanship," he said.