Omarosa claims Donald Trump is holding wife Melania hostage

Omarosa Manigault-Newman has made the astonishing claim that President Donald Trump might deport First Lady Melania if she tried to leave him while he holds office.

It is the latest Trump-bashing claim to emerge from the new memoir, Unhinged, by Manigault-Newman, who was fired from the White House in December for alleged "integrity violations".

"If Melania were to try to pull the ultimate humiliation and leave him while he's in office, he would find a way to punish her," Manigault-Newman wrote in the book, according to the Mercury News.

Manigault-Newman implied that Trump played some nefarious role in Melania's immigration to the US from Slovenia in 1996 - even though the couple are believed to have first met two years later, in 1998, reports Daily Mail.

"This is a man who has said he could pardon himself from the Mueller investigation. Why not pardon himself over an alleged visa payoff?" wrote Manigault-Newman.

Questions have been raised in the past about how Melania, who worked as a fashion model, obtained a so-called "Einstein" EB-1 visa for people in the tops of their fields - though immigration lawyers say there is nothing particularly unusual about a top model being granted the visa.

Melania became a US citizen in 2006, one year after her marriage to Trump.

The First Lady and Trump are seen on the White House lawn last month. They met in 1998 when she was a model in Manhattan, and have been married since 2005. Photo / AP

In recent months, the Trump administration has made moves to strip citizenship from those who lied or otherwise cheated in the naturalization process. Manigault-Newman implies that Trump may have had personal motivations for the policy move, intending to hold the threat of deportation over his wife's head.

"Since Donald is fully aware of however she acquired her permanent citizenship, he could, if there were anything fishy around it, expose the methods and somehow invalidate it," wrote Manigault-Newman.

"He is a vindictive man, and I would not put anything past him."

"In my opinion," she added, "Melania is counting every minute until he is out of office and she can divorce him."

Stephanie Grisham, the first lady's communications director, refuted Manigault-Newman's claims in a statement to the News.

"Mrs Trump rarely, if ever, interacted with Omarosa. It's disappointing to her that she is lashing out and retaliating in such a self-serving way, especially after all the opportunities given to her by the President," Grisham said in a statement.

White House Press Secretary Sarah Sanders has previously dismissed the claims in Manigault-Newman's book, saying it is "riddled with lies and false accusations".