Former FBI director James Comey declined to pledge loyalty to President Donald Trump during a dinner the men shared in January, The New York Times reports.
The newspaper quotes two unnamed Comey associates who say they heard Comey's account of the dinner.
Comey instead promised Trump "honesty".
When Trump then pressed for "honest loyalty", Comey told the president "you will have that", say the associates, who told the Times they agreed to keep the story confidential while Comey was FBI director.
White House spokeswoman Sarah Huckabee Sanders disputed the report.
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But the account echoes wording in a comment made a day earlier to the Associated Press by longtime Comey friend Daniel Richman, who said the president had removed "somebody unwilling to pledge absolute loyalty to him".
