DUBAI/ISTANBUL (Reuters) - Human rights groups are calling on Saudi Arabia to verify the whereabouts of prominent Saudi journalist Jamal Khashoggi, who has been missing for three days after entering the Saudi consulate in Istanbul earlier this week.
Turkish and Saudi authorities have offered conflicting accounts of his disappearance, with Ankara saying there is no evidence he left the diplomatic mission and Riyadh saying that he exited the same day.
Khashoggi, who has lived in self-exile in Washington for the past year fearing retribution for his critical views, entered the consulate on Tuesday to secure documentation for an upcoming marriage, according to his fiancée, who waited outside.
If Saudi Arabia detained Khashoggi without acknowledging it, his detention would constitute an enforced disappearance, Human Rights Watch said in a statement late on Thursday. It called on Turkey to deepen its investigation into the case.
"The burden of proof is on Saudi Arabia to produce evidence for its claim that Khashoggi left the consulate alone, and that Saudi agents have not detained him," said Sarah Leah Whitson, Middle East director at the New York-based group.
Saudi authorities could not be reached for comment on the HRW statement. Riyadh has denied that Khashoggi is in Saudi custody.
Press freedom watchdogs also raised red flags, while the Washington Post, which has regularly featured Khashoggi's writing since last year, published a blank space where his column would normally appear.
"Given the Saudi authorities' pattern of quietly detaining critical journalists, Khashoggi's failure to emerge from the Saudi consulate on the day he entered is a cause for alarm," said Sherif Mansour, Middle East and North Africa Program Coordinator for the Committee to Protect Journalists.
Sophie Anmuth, head of the Middle East desk for Reporters Without Borders, called on both governments to ensure Khashoggi reappears quickly.
"Until otherwise demonstrated, he is still inside the Saudi consulate in Istanbul and the Saudi authorities are responsible for his safety and well-being," she said in a statement.
Hatice Cengiz, Khashoggi's fiancée, told Reuters he had been concerned about a crackdown on dissent in the kingdom, but assumed he was safe outside the country.
Turan Kişlakçı, a friend who heads the Arab Turkish Media Association, said Khashoggi received assurances from Saudi officials before his visit that he could enter safely.
Turkish presidential spokesman Ibrahim Kalin told reporters that Khashoggi remained in the consulate and the authorities were negotiating with the Saudis to resolve the issue.
The consulate said it was working with the Turkish government to "uncover the circumstances" of his disappearance.
Khashoggi is a familiar face on political talk shows on Arab satellite television networks and used to advise Prince Turki al-Faisal, former Saudi intelligence chief and ambassador to the United States and Britain.
Over the past year, he has written columns inveighing against Saudi policies towards Qatar and Canada, the war in Yemen and a crackdown on dissent which has seen dozens of people detained.
Washington Post editorial page editor Fred Hiatt said the newspaper had reached out to "anyone we think might be able to help locate him and assure his safety," including U.S., Turkish and Saudi officials.
Saudi Arabia is ranked 169th out of 180 countries in RSF's 2018 World Press Freedom Index, a few places behind Turkey. All public protests are banned in the kingdom, as are political parties.
(Reporting by Stephen Kalin, Sarah Dadouch, Katie Paul and Ezgi Erkoyun; Editing by Mark Heinrich)