The mystery of Washington Post contributor Jama Khashoggi’s disappearance took a grim turn over the weekend as Turkish investigators claimed that an execution squad dispatched from Saudi Arabia murdered Khashoggi within the walls of the Saudi consulate in Istanbul.

Khashoggi has not been seen or heard from since last Tuesday when he entered the consulate to obtain some paperwork related to his divorce. His new fiancee, who was holding his cell phone and waiting for him outside, reported his disappearance when he did not emerge after 12 hours.

Saudi officials, including Crown Prince Mohammed bin Salman, have said Khashoggi departed the facility soon after collecting the papers he needed and must have disappeared at some point afterward. Turkish police responded there are cameras watching the consulate at all times and they did not record his departure.

The Washington Post on Sunday quoted two sources with knowledge of the Turkish investigation into Khashoggi’s disappearance who said the journalist was killed inside the consulate by a 15-member team sent from Saudi Arabia to conduct a “pre-planned murder.”

The Post noted that the sources offered no proof of this accusation. Turkish media seem absolutely convinced Khashoggi was “barbarically murdered,” as the head of the Turkish-Arab Media Association put it on Monday, and Turkish police will present “concrete evidence” soon.

The Saudi consul-general allowed reporters to tour the facility on Saturday to satisfy themselves that Khashoggi was not held within. Turkish officials hypothesized that Khashoggi has been spirited out of the consulate, either alive or dead. In fact, one Turkish official told his U.S. counterparts that Khashoggi’s body was dismembered, packed into boxes, and shipped out of Turkey for disposal.

The consulate denounced “baseless allegations” of murder and implied the team from Saudi Arabia referenced in the Post story was a “security delegation of Saudi investigators” sent to Istanbul to investigate Khashoggi’s disappearance.

Turkish authorities on Monday requested permission to conduct a thorough search of the Saudi consulate, following a meeting between Turkish Deputy Foreign Minister Sedat Onal and the Saudi ambassador.

CBS News and the Associated Press speculated Khashoggi might have been detained or killed because he has ties to an out-of-power branch of the Saudi royal family and has been strongly critical of Crown Prince Mohammed bin Salman’s policies, particularly with respect to Qatar, Iran, and what the CBS/AP refers to as “moderate Islamist” groups:

In the Sept. 23 interview, he called Saudi Arabia’s foreign policy “narrow minded,” and ridiculed its crackdown on political Islam, urging the kingdom to realign its policy to partner with Turkey, a close Qatar ally.

“Saudi is the mother and father of political Islam. It is based on political Islam,” Khashoggi said. “The only recipe to get Iranians out of Syria — it is not Trump or anyone else — it is through the support of the Syrian revolution. … Saudi Arabia must return to supporting the Syrian revolution and partnering with Turkey on this.”

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“As of now, I would say Mohammed bin Salman is acting like Putin. He is imposing very selective justice,” Khashoggi wrote in the Post last year after he fled the kingdom, saying he feared returning home.

Writing at the Washington Post on Sunday, analyst Ishaan Tharoor predicted Khashoggi’s disappearance could be “the moment that Saudi Arabia finally loses Washington.” He noted expressions of concern from Senators Marco Rubio (R-FL) and Chris Murphy (D-CT) on Twitter:

Tharoor blamed the Trump administration for indulging Saudi abuses while relentlessly criticizing Iran and envisioned Khashoggi’s incarceration or murder as the last straw for congressional representatives uncomfortable with the size of the blank check given to Mohammed bin Salman to consolidate his power.

CNN National Security Analyst Peter Bergen advanced a similar argument on Monday, granting there is “much to praise” in the accomplishments of the Crown Prince but worrying that the Kingdom has paradoxically liberalized by becoming a “secularizing totalitarian dictatorship.” Bergen called for U.S. sanctions against Saudi Arabia if Saudi involvement in Khashoggi’s disappearance can be proved, noting that he is a legal U.S. resident and an employee of the Washington Post.