One of the team of Saudis who killed journalist Jamal Khashoggi last month reportedly told a superior over the phone to “tell your boss” that the mission had been carried out, in what is believed to be a reference to Crown Prince Mohammed bin Salman.
The remarks, which were said to have been picked up in a recording collected by Turkish intelligence, were made shortly after the journalist, a US resident, was killed in the Saudi consulate in Turkey, three people familiar with the recording told the New York Times.
The newspaper said the clip was shared last month with the CIA. director, Gina Haspel, and is regarded by intelligence officials as some of the strongest evidence linking Prince Mohammed - the country's de facto leader - to the killing of the Washington Post columnist on October 2.
The person speaking in Arabic during the recording is Maher Abdulaziz Mutreb, one of the 15 Saudis sent to Istanbul to confront Mr Khashoggi, the paper reported. The prince was not mentioned by name.
Mr Mutreb is a security officer who frequently travelled with Prince Mohammed, while the other person on the call is believed to be one of the prince’s aides.
Mr Mutreb also said words to the effect of “the deed was done”, the sources told the paper.
In a statement to the Times on Monday, Saudi officials denied the crown prince “had any knowledge whatsoever” of Mr Khashoggi’s killing. Referring to phrase “tell your boss,” the Saudi statement said Turkey had “allowed our intelligence services to hear recordings, and at no moment was there any reference to the mentioned phrase in the such recordings.”
Riyadh, already under scrutiny for civilian deaths in Yemen air strikes, is facing global criticism and potential sanctions over Mr Khashoggi's killing inside its Istanbul consulate.
Britain has called for a "credible" investigation. Jeremy Hunt, the Foreign Secretary and the first British minister to visit Saudi Arabia since the killing, said its results had to be reviewed before deciding on any consequences.
"I talked very frankly about our concerns about what happened and how important it is for Saudi’s strategic partners to know that this cannot and will not happen again," Mr Hunt told Reuters in an interview.
"Due process is in train at the moment in Saudi Arabia, and I was led to believe there will be rapid progress in making sure that people are brought to justice," he said.
Mr Hunt said accountability was needed for both the people who committed the act and those who ordered it.
Turkish President Tayyip Erdogan says Mr Khashoggi's murder was ordered at the highest levels of the Saudi government, and some US lawmakers have accused Prince Mohammed bin Salman of doing so.
After initial denials, Saudi officials acknowledged the killing was planned in advance but said the crown prince had no knowledge of the specific operation.
Mr Erdogan said on Saturday that Turkey had given recordings related to the killing to countries including Britain.
Asked about the recordings, Mr Hunt declined to comment on intelligence matters but said: "My understanding of what actually happened is not dissimilar to what I’ve been reading about in the newspapers."