Saudi Crown Prince Mohammed Bin Salman told the US he considered murdered writer Jamal Khashoggi to be a dangerous Islamist.
Media reports say Prince Mohammed said this in a phone call with the white house after Khashoggi disappeared but before Saudi Arabia admitted killing him.
Saudi Arabia has denied the reports in the Washington post and New York Times.
Khashoggi, a Saudi national working for the US press, was a well-known critic of his home country's rulers.
His body has not yet been found, but turkey, the US and Saudi Arabia have all agreed that he was killed at the Saudi consulate in Istanbul on 2 October.
Saudi Arabia denies its royal family was involved and says it is "determined to find out all the facts".
Late last month, Prince Mohammed said that "the crime was painful to all Saudis".