The CIA reportedly believes Saudi Crown Prince Mohammed bin Salman ordered the killing of journalist Jamal Khashoggi in Istanbul, complicating President Donald Trump's efforts to preserve ties with a key US ally.
Citing sources, Reuters said on Friday the CIA had briefed other parts of the US government, including Congress, on its assessment, which contradicts Saudi government assertions Prince Mohammed was not involved.
The CIA's finding, first reported by the Washington Post, is the most definitive US assessment to date tying Saudi Arabia's de facto ruler directly to the killing.
The Saudi Embassy in Washington rejected the claims as false.
"We have and continue to hear various theories without seeing the primary basis for these speculations," a spokeswoman for the embassy said in a statement.
US Vice President Mike Pence, on a visit to Papua New Guinea, told reporters travelling with him he could not comment on classified information.
"The murder of Jamal Khashoggi was an atrocity. It was also an affront to a free and independent press and the United States is determined to hold all of those accountable who are responsible for that murder," he said but added that Washington wanted to preserve its relationship with Saudi Arabia.
The State Department declined to comment.
Trump and top officials of his administration have said Saudi Arabia must be held to account for any involvement in Khashoggi's death but have also stressed the importance of the alliance.
US officials have said Saudi Arabia, a major oil supplier, plays an important part in countering Iran's malign role in the region and Trump has repeatedly said he does not want to imperil US arms sales to the kingdom.
While the Trump administration on Thursday imposed sanctions on 17 Saudis for their role in Khashoggi's killing, many in Congress think the United States should take a tougher stance, and the CIA's findings are likely to embolden that view.
Khashoggi, a critic of the Saudi government and a columnist for the Washington Post, was killed at the Saudi consulate in Istanbul on October 2 when he went there to pick up documents he needed for his planned marriage to a Turkish woman.
Khashoggi had resisted pressure from Riyadh for him to return home.
Saudi officials say a team of 15 Saudi nationals were sent to confront Khashoggi at the consulate and he was accidentally killed in a chokehold by men trying to force him to return to the kingdom.
Turkish officials say the killing was intentional and have pressured Saudi Arabia to extradite those responsible to stand trial.
An adviser to Turkish President Tayyip Erdogan has accused Saudi Arabia of a cover-up.