ISTANBUL — Turkish President Recep Tayyip Erdogan demanded Monday that Saudi Arabia prove that journalist Jamal Khashoggi left the Saudi consulate in Istanbul on his own as Saudi officials have repeatedly asserted after he disappeared last week while inside the mission.

Erdogan’s comments were his most direct suggestion yet of potential Saudi culpability in Khashoggi’s disappearance and came after other Turkish officials have said they believe that he was killed by Saudi agents inside the consulate.

“Do you not have cameras and everything of the sort?” Erdogan said of the consular officials. “They have all of them. Then why do you not prove this? You need to prove it.”

Turkey’s foreign ministry summoned the Saudi ambassador to urge “full cooperation” in the investigation into Khashoggi’s disappearance, the official Anadolu news agency said Monday.

The ambassador was called to the ministry in the Turkish capital, Ankara, on Sunday, the agency said. It was the second time Turkey has summoned the ambassador since Khashoggi failed to emerge after a visit to the consulate on Oct. 2.

Turkish officials have said they believe Khashoggi, 59, a critic of the Saudi leadership and a contributor to The Washington Post’s Global Opinions section, was killed by a team of 15 Saudis flown in specifically to carry out the attack. Saudi authorities have called the charges “baseless.”

The incident has angered rights activists and press freedom advocates, who have called on the Saudi government to clarify Khashoggi’s whereabouts. It has also raised tensions between regional rivals, Turkey and Saudi Arabia.

Turkey has yet to make any evidence public. The private Turkish broadcaster NTV reported Monday that police had requested access to the Saudi Consulate in Istanbul. It was unclear whether the police were granted access or if they would search the diplomatic mission in Istanbul’s Levent district at a later date.

Another report Monday in the daily newspaper Sabah said investigators were also focused on a convoy of diplomatic vehicles that departed from the consulate on the day Khashoggi vanished. A U.S. official said Turkish investigators believe Khashoggi was likely dismembered, removed in boxes and flown out of the country.

In a meeting with The Washington Post’s publisher, Fred Ryan, the Saudi ambassador to the United States said Sunday night that it was “impossible” that such a crime could be covered up by consulate employees “and we wouldn’t know about it.”

President Trump and House Speaker Paul Ryan have joined the ranks of U.S. officials raising concerns about Khashoggi’s disappearance. The president said “I am concerned about it,” and Ryan called the disappearance “very disturbing” and said the U.S. needs “clear facts” on the situation.