La Toya Jackson is being sued by her 'Celebrity Apprentice' co-star.

Omarosa Manigault has announced her intentions to file a lawsuit against the singer over comments made on the show, claiming the reality TV star caused her fiancé - late 'Green Mile' actor Michael Clarke Duncan - to suffer a heart attack and ''pulled the cord'' on his life support.

Quizzed about rumours she planned to sue her rival, Omarosa told Howard Stern's during an interview on his radio show: ''Not planning to, I'm going to. She said really nasty things about Michael.

''She said he had a heart attack and, 'I know she caused it. He was on life support and she went in and pulled the plug.'''

The shocking diatribe was filmed late last year but only aired on US TV earlier this month, and Omarosa, 39, feels her co-star has had ample time to apologise, however, she claims La Toya has instead repeated her scathing comments on various talk shows.

She added: ''[I] gave her the time to retract it and now we'll both be spending money on lawyers.

''It's only actionable if she repeats it. It's called reckless disregard for the truth. She said it back in October. She's repeated it subsequently on all of these talk shows.''

The feisty duo clashed several times on the Donald Trump-hosted reality competition and La Toya, 56, blamed her rival for her firing on the show, calling her ''the most evil person I have ever met''.

After being axed by Donald, she said: ''Omarosa's fiancé passed away not long ago. He had a heart attack. I'm sure she gave it to him.

''She's a conniving, scheming, cut-throat, probably pulled the cord on Michael Clarke Duncan.''

The 'Daredevil' star, who dated Omarosa for two years, died in September 2012 while in intensive care following a heart attack in July.