In a scathing column for the Daily Mail, Morgan called Omarosa "relentlessly loathsome," "vicious" and "conniving," and accused her of propositioning him for sex.
The journalist claims that during their time on Celebrity Apprentice together, she lobbed the idea of a "showmance" his way in order to help both their games in the reality TV competition.
When he asked for clarification of said "showmance," Omarosa allegedly replied: "A showmance. You know, a romance on the show — we get it on together. Happens all the time on Apprentice. Everyone has sex together. Then we can make lots of money out of it."
When Morgan said he turned down her offer, calling her a "deluded woman," he says she didn't take it well.
"What are you? Gay?" she allegedly asked Morgan, who says from then on, Omarosa "turned on me like a viper."
"Because I’d rejected her revolting sex plot, she decided the best line of attack was to repeatedly question my sexuality in the most crude and offensive manner imaginable," Morgan wrote.
He wrote that she once said to him, "Shut the f— up, a—hole. How are your kids going to feel when they wake up and discover their dad’s a f—ing f—t?’"
Morgan also claims that in another instance, "in front of boxing champion Lennox Lewis, she said: ‘Hey Piers, I hear you got caught sucking a gay waiter’s c— in a hotel pool?’"
He says that eventually, Omarosa "took her bigotry to the boardroom" where she told Donald Trump, "‘I think Piers is in the closet.'"
"Omarosa is a reprehensible human being, prepared to offer sex to win a reality TV show and use the most vile homophobic slurs against rival contestants," Morgan railed, accusing her of doing so "purely so it would bring her more air time, and more attention."
Morgan then wondered why there was no public outcry about Omarosa working in the White House, where he says she was "allowed to roam free."
"I was aghast when she joined Trump’s campaign team in July 2016 as a the ‘director of African-American outreach,’" Morgan wrote. "I haven’t met an African-American in the whole country who would ever like to be ‘reached out’ to by Omarosa."
"My disquiet turned to utter horror when Trump won the presidency and Omarosa was appointed the White House’s director of communications for the Public Liaison Office," he continued, writing that her tenure "went exactly how I expected."
Morgan continued, arguing that although Trump "prides himself on only backing winners," he took Omarosa with him to the White House — after Morgan beat her on Celebrity Apprentice.
"In our Celebrity Apprentice season, she was fired when we were rival project managers, after I destroyed her in a challenge in what Trump called ‘the greatest slaughter in the history of the Apprentice,’" Morgan wrote. "Yet he took this serial loser, and horrible human being, into the heart of the White House to spread her poison.
Omarosa is currently sequestered in the Celebrity Big Brother house, where she will remain until either she is evicted or she wins the reality competition.
She has been openly discussing her time in the White House, where she worked up until a few weeks ago. She told Ross Mathews that she would "never" vote for Donald Trump again and told the rest of the houseguests that "As bad as y'all think Trump is, you would be worried about Pence. So everybody that's wishing for it, might want to reconsider their lives."
"We would be begging for the days of Trump back, if Pence became president, that's all I'm saying," she added.
The next episode of Celebrity Big Brother airs Wednesday on CBS.