Omarosa Manigault, a staffer for US President-elect Donald Trump, listens as Martin Luther King III speaks to the media after meeting with the President-elect at Trump Tower in New York City on January 16, 2017.

The White House on Friday blasted a new book by former Trump aide Omarosa Manigault Newman as "riddled with lies and false accusations" after reports that she wrote that President Donald Trump is a "racist" who was caught on tape using the N-word multiple times.

Former "Apprentice" contestant Manigault Newman cites three sources in her book, "Unhinged: An Insider Account of Trump's White House," as telling her that there is a tape of Trump using that offensive racist term for black people during filming of that reality show he starred in for years.

"It had finally sunk in that the person I'd thought I'd known so well for so long was actually a racist," Manigault Newman reportedly wrote in her book.

"Using the N-word was not just the way he talks but, more disturbing, it was how he thought of me and African-Americans as a whole."

Manigault Newman says she never directly heard the president say the N-word,

On Friday, NBC News reported that in her book, Manigault Newman also has written that 24 hours after she left White House employment Trump's daughter-in-law, Lara Trump, emailed her a contract to work on the president's re-election campaign for $15,000 per month.

The contact came with a nondisclosure agreement that sought to bar Manigault Newman from "ever talking about the entire Trump family or the entire Pence family, to anyone in the universe, for all of eternity," she wrote.

"I declined the offer. I was done with Trumpworld."

Earlier this week, The Daily Beast reported that Manigault Newman, while serving as assistant to the president and director of communications for the Office of Public Liaison, secretly recorded conversations she had with Trump.

She left the White House in late 2017.

Trump's spokesman has said she was fired, but she claims to have left on her own accord.

White House spokesman Sarah Huckabee Sanders, in a statement on Manigault Newman's book, said Friday: "Instead of telling the truth about all the good President Trump and his administration are doing to make America safe and prosperous, this book is riddled with lies and false accusations."

"It's sad that a disgruntled former White House employee is trying to profit off these false attacks, and even worse that the media would now give her a platform, after not taking her seriously when she had only positive things to say about the President during her time in the administration," Huckabee Sanders said.