There are reports the disfigured body of missing Saudi journalist Jamal Khoshoggi has been found.
Sky News says two sources have them Mr Khoshoggi had been "cut up", and his face "disfigured".
One of the sources suggested his remains were found in the garden of the Saudi consul's home in Istanbul.
King Salman and Crown Prince Mohammed bin Salman offered their condolences to Khashoggi's brother and son during a meeting at the royal palace in Riyadh, official Saudi news agency SPA reports.
Turkey's president Erdogan also offered his condolences to Khashoggi's family in a phone call on Tuesday (local time), according to state news agency Anadolu.
Mr Khashoggi went missing when visiting the Saudi consulate in Istanbul three weeks ago.
After denying knowing what happened to him, Saudi Arabia has since admitted the Washington Post columnist, an opponent of Saudi ruler King Salman, died in a fistfight.
Turkish President Recep Tayyip Erdogan says he wants Saudi Arabia to allow 18 suspects that it detained for the journalist's killing to be tried in Turkish courts.
"To blame such an incident on a handful of security and intelligence members would not satisfy us or the international community," Erdogan said in a speech to ruling party lawmakers in parliament.
"Saudi Arabia has taken an important step by admitting the murder. As of now we expect of them to openly bring to light those responsible — from the highest ranked to the lowest — and to bring them to justice," said the Turkish president, who used the word "murder" 15 times in his speech.