Saudi Crown Prince, Mohammed bin Salman attends the second day of the Future Investment Initiative conference, in Riyadh, Saudi Arabia, Oct. 24, 2018. Credit: Amr Nabil | AP

People who’ve heard a recording of Saudi columnist Jamal Khashoggi’s murder don’t believe it implicates Saudi Arabia’s de facto ruler, U.S. National Security Adviser John Bolton said, weighing in on a controversy that has sharply raised international pressure on the top oil exporter.

Speaking in Singapore, where he’s attending a regional summit, Bolton said he hadn’t heard the recording himself. Asked if the audio links Crown Prince Mohammed bin Salman to the killing, Bolton said: “That’s not the conclusion I think that the people who heard it have come to, and that’s certainly not the position of the Saudi government.”

“The president has made it clear he wants to get to the bottom of this,” Bolton told reporters Tuesday.

His comments came as The New York Times reported that a member of the kill team instructed a superior over the phone to “tell your boss” — believed to be Prince Mohammed — that the mission had been accomplished. The recording is seen by intelligence officers as some of the strongest evidence linking the power behind the Saudi throne to the murder, the report said, citing three unidentified people familiar with the recording.

Khashoggi, a former palace insider who turned critic, was strangled to death at the Saudi consulate in Istanbul on Oct. 2 and his body dismembered, the city’s chief prosecutor has said. Turkey has stopped just short of blaming Prince Mohammed, the 33-year-old who runs the affairs of the kingdom day to day. Saudi Arabia has vehemently denied he had any knowledge of the operation, which authorities initially denied then said was an interrogation gone wrong.

The high profile of Khashoggi, a U.S.-based Washington Post contributing columnist, and the drip-drip of sensational leaks about his demise have provoked a global outcry and tarnished the reputation of the brash young prince, whose efforts to cast himself as a bolder reformer and trusted U.S. ally have often chafed against his policies abroad.

Prince Mohamed loosened restrictions on women and sought to prepare the economy for a time after oil but also embroiled his country in a war in Yemen, led a boycott of Qatar and engaged in diplomatic spats with Germany and Canada. Last year, Saudi Arabia arrested dozens of billionaires and princes in a crackdown on corruption that the business community read as a shake-down.

The controversy, and Turkey’s success in keeping it on the global news agenda for weeks, has embarrassed foreign investors and hardened stances even among key Saudi allies.

Turkish President Recep Tayyip Erdogan said his country’s intelligence service had hidden “nothing” from foreign counterparts and that officials from many countries, including Saudi Arabia, had listened to voice recordings of the killing.

According to comments published in Hurriyet newspaper, Erdogan said a Saudi intelligence office who listened to the audio was “shocked” and commented that those involved must have been on drugs.

“It’s obvious that this murder was premeditated and that the order came from above,” it cited Erdogan as saying on his way back from Paris where he met President Donald Trump. “Eighteen people are under arrest in Saudi Arabia. The murderers are certainly among them. It should be uncovered who gave the order to kill.”

Initially reluctant to take measures against a Gulf ally it needs to keep oil prices under control as it tightens sanctions against Iran, the U.S. has demanded that Riyadh begin talks by the end of this month to end the war in Yemen.

Trump now says Saudi Arabia misused U.S.-supplied weapons in the Saudi-led coalition’s bombing campaign in Yemen, which has helped trigger the world’s worst humanitarian crisis. The two countries announced Saturday the U.S. will also stop refueling Saudi jets participating in the conflict. With Democrats winning control of the U.S. House of Representatives in midterm elections this month, pressure is unlikely to ease.

Saudi Arabia has yet to respond to the latest revelations. Turkish police haven’t been able to locate the columnist’s remains despite extensive searches, and an aide to Erdogan said his body may have been dissolved.