Two days before entering the Saudi consulate in Turkey, Jamal Khashoggi appeared at Middle East Monitor's conference on the legacy of the Oslo Accords in London.
The journalist's fiancee, Hatice Cengiz, said on Twitter she was "waiting for an official confirmation from the Turkish government" before she could believe the claims.
"The Saudis are saying we can come to investigate, but they have of course disposed of the body", he said, adding that he believed Saudi statements about a lack of footage from security cameras were insincere.
"The consulate officials can not save themselves by simply saying "he has left".
Khashoggi, a Washington Post contributing writer who had been critical of the Salman government, has been living for a year in self-imposed exile in the United States after a Riyadh crackdown on dissent in the kingdom.
Turkey has summoned the Saudi ambassador to request the kingdom's "full cooperation" in an investigation into the disappearance of Khashoggi, a Washington Post contributor who wrote articles critical of the Kingdom's ruling elite.
The first pictures have emerged of the missing journalist Jamal Khashoggi entering the Saudi consulate in Istanbul amid new details of the day of his disappearance.
Khashoggi said Saudis were expected to "accept, with gratitude, the social reforms that I have long called for while keeping silent on other matters - ranging from the Yemen quagmire, hastily executed economic reforms, the blockade of Qatar, discussions about an alliance with Israel to counter Iran, and last year's imprisonment of dozens of Saudi intellectuals and clerics".
Now Turkish authorities are saying there is evidence to suggest the journalist never left the building and was murdered there. The UK foreign office said reports Khashoggi was abducted or killed by the Saudi government were "extremely serious allegations". However, ties have been strained by the president's recent comments implying Saudi Arabia wouldn't last "two weeks" without USA guaranteeing its safety as global oil prices continue to rise.
His disappearance is likely to further deepen divisions between Turkey and Saudi Arabia.
On Sunday, Turkish President Erdogan said that it was very saddening that Khashoggi disappeared in Turkey.
CNN reported Sunday that the United States government is quietly working Khashoggi's case across several agencies and at senior levels of the administration.
God willing, we will not be faced with an undesirable situation we do not want.
On Tuesday, a picture of a man said to be Khashoggi, entering the Saudi consulate in Istanbul was shared on social media, allegedly showing him entering shortly before his disappearance.
In a statement carried by Saudi Press Agency, the official strongly denounced these baseless allegations. Turkey, it said, must back up its conclusion Khashoggi was killed by making public any evidence it has.
Saudi Arabia's consul in Istanbul opened his mission to Reuters on Saturday in an effort to show that Khashoggi was not on the premises. "This case sends a shockwave among Saudi Arabian human rights defenders and dissidents everywhere, eroding any notion of seeking safe haven overseas". "Turkish officials have said they believe he was killed inside in a planned murder". "This is a horrific escalation in the crown prince's campaign to silence dissent, to silence any criticism, even the mildest of criticism, from Saudis at home or overseas", says columnist for The Intercept Mehdi Hasan, who is also host of "UpFront" at Al Jazeera English, where he interviewed Khashoggi earlier this year.