Prince Andrew has been accused of using a racial slur during a meeting by a former Downing Street advisor.
The claim was made by Rohan Silva, who was David Cameron's key aide on the tech economy at the time.
He said the incident occurred at Buckingham Palace in 2012 during a discussion about trade policy.
In an article for the Evening Standard, Silva said he asked the Prince whether the government trade department could be doing a better job.
"Well, if you'll pardon the expression, that really is the n****r in the woodpile," Silva claims the Prince replied.
Sources at Buckingham Palace deny that the Prince used the phrase and said he would never use that language, the Evening Standard reported.
Silva said he was ashamed he didn't do anything at the time and kicked himself for never confronting the Prince on his choice of words.
"The meeting ended shortly afterwards, and I remember distinctly how I walked blinking into the sunshine outside Buckingham Palace, reeling at the Prince's use of language," he wrote.
Silva claims this isn't the first time the Prince has used a racial slur.
While the pair were discussing European Union reforms, Silva was interrupted by him.
"What you have got to remember is that you'll never get anywhere by playing the white man," the Prince allegedly said.
The phrase 'playing the white man' refers to a colonial expression meaning only white people can be trusted to follow the rules.
The claims come after the Prince's interview with BBC Newsnight on Saturday (local time) where he was questioned about his links to the late convicted sex offender, Jeffrey Epstein.
During the interview, the Prince denied having sex with Virginia Giuffre, an alleged Epstein sex slave, and claimed he was at a pizza restaurant with his daughter, Princess Beatrice.
