Turkish President Recep Tayyip Erdogan said Saudi Arabia should prove that missing Saudi journalist Jamal Khashoggi has, in fact, left the Saudi consulate in Istanbul.
"He entered the general consulate himself and if he has entered by himself and if he did not exit it, of course this should be proven by the general consulate," Erdogan said at a press conference in Budapest.
Erdogan said the Saudi consulate should have CCTV cameras and should be able to show the video of Khashoggi leaving the building. He mentioned that there are no documents or evidence that show the journalist departing.
The Justice Ministry and the chief prosecutor in Istanbul "started an investigation and efforts are continuing," Erdogan said. Airport entrances and exits are being investigated.
"At the moment there are certain people who arrived from Saudi Arabia. And our chief investigator is investigating everything in this matter."
Turkey has asked for permission to search the consulate in Istanbul in the wake of Khashoggi's disappearance, state broadcaster TRT said. That move comes as Turkey also summoned Saudi ambassador Sedat Onal for a second time in recent days on Sunday, asking the diplomat for his "full cooperation" in the investigation.
These are the latest developments in Turkey's probe into the disappearance of Khashoggi, a Washington Post writer and Saudi royal court insider-turned-critic. Turkish officials told several media organizations that he had been murdered inside the consulate.
Saudi Arabia has strenuously denied any involvement in Khashoggi's disappearance.
Khashoggi, who left Saudia Arabia in 2017, entered the building on Tuesday to obtain documents for his upcoming marriage while his Turkish fiancée waited outside. But she says she never saw him re-emerge.
A Saudi official said Khashoggi left the consulate shortly after he visited. The Saudis did not, however, release any surveillance footage or other evidence.
The incident has thrown sharp focus on Saudi Arabia's young Crown Prince Mohammed bin Salman's perceived crackdown on dissidents, his kingdom's delicate relationship with Turkey, and Khashoggi 's influence within the royal court.
Turkish President Recep Tayyip Erdogan on Sunday called Khashoggi a "friend" he had known for some time, and vowed to personally "chase" the investigation into his disappearance.
Turkish police are also examining all the consulate's entry and exit records, from the time Khashoggi entered the building until his fiancée lost contact with him.
Turkish officials: Khashoggi was killed in consulate
Four days after Khashoggi vanished, unnamed Turkish officials told the The Washington Post and Reuters that the journalist was killed inside the consulate. The officials have so far provided no evidence or details of how they arrived at this conclusion.
Yasin Aktay, a political adviser to Erdogan, told CNN on Sunday that he too believes there is a strong possibility that Khashoggi was killed inside the Saudi consulate.
"I personally think the possibility of him being killed is stronger than other possibilities, although I do not want to accept it. Because if he was alive, Saudis would provide evidence that he is alive," Aktay told CNN during a telephone interview in Istanbul.
"If he is not in the consulate and if he did not leave through the normal ways, he might have left sedated or left in pieces."
Aktay, who is also an adviser to the ruling AK Party, told CNN that said the Turkish government is not "ignoring any piece of evidence," and said the Saudis are not "sharing any convincing explanations on what happened inside the building."
Fifteen Saudi Arabian nationals -- including several officials -- arrived in Istanbul on two planes and visited the Saudi consulate there on the day Khashoggi went missing, state-run Anadolu news agency reported Saturday, citing police sources. The 15 Saudis have all since left Turkey, it added.
As demands for answers grew, Saudi officials gave journalists a tour Saturday of the six-story building in an effort to prove Khashoggi was not inside. Reuters said that a consular official showed them every room, even opening up cupboards and filing cabinets. No sign of him was found.
On Sunday, Khashoggi's family in Saudi Arabia appeared to distance themselves from media reports of his death, saying in a statement to the Saudi-owned Al Arabiya news channel: "We trust the government and the actions taken by it and all the efforts being made in the case of Jamal Khashoggi."
Who is Jamal Khashoggi?
Khashoggi, known in part for his interviews with terror mastermind Osama bin Laden, was a Saudi royal court insider before he left Saudi Arabia in 2017 for Washington. He began to contribute opinion pieces to The Washington Post that were critical of bin Salman's policies, including his consolidation of power. He was named a contributing writer at the Post in January.
Khashoggi is a Virginia resident, according to his congressman, Rep. Gerry Connolly. He had applied to be a permanent US resident, but at this time his exact residency status remains unclear.
Pressure is now mounting on the US to weigh in on the disappearance, which could have serious implications for the precarious relationship between Saudi Arabia and Turkey, already opposed over the blockade by Saudi Arabia and other Gulf states against Qatar.
Two senior US administration officials told CNN on Sunday that although Washington is not commenting publicly, and has no information confirming the Turkish claims, the administration is quietly working across several agencies, seeking answers about Khashoggi's whereabouts and talking to senior Saudi officials.