Mariah Carey’s older brother is suing the star for defamation and emotional distress caused by her recent memoir, The Meaning Of Mariah Carey.
Morgan Carey, who is seeking unspecified damages, says the book falsely suggests he was violent.
As a result he has suffered “extreme mental anguish” and “serious damage to his reputation”, his legal case says.
The papers have been filed a month after Mariah’s sister sued her for $1.25m (£900,000) over the memoir.
Alison Carey said passages claiming that she gave Valium to 12-year-old Mariah, tried to pimp her out and threw boiling tea on her were “outrageous” and meant to “humiliate and embarrass” her.
She denied the claims, saying the singer had “presented no evidence to substantiate these serious allegations”.
Mariah’s autobiography was published last September and topped The New York Times’ non-fiction best-seller list in October.
It contains many revelations about her life, including her difficult, dysfunctional upbringing, the racism she encountered as a child, and allegations that her first marriage to record executive Tommy Mottola was abusive.
Morgan Carey, born in 1960, says the star has damaged his reputation by writing about an alleged “vicious fight” with his father that occurred when she was a little girl.
Mariah wrote that it took “12 cops to pull my brother and father apart” – but Morgan says the incident was “fictional” and that, under normal circumstances, only one or two police officers would have responded to a domestic violence report.
He has also sued over passages that, he says, imply he tried to extort money from Mariah after she became successful; and that he had been “in the [criminal justice] system”.
“[Morgan] brings this action more in sorrow and disappointment in his sister’s betrayals and malicious falsehoods than in anger at them,” papers filed in Manhattan read.
“He is by no means envious of his sister’s enormous artistic and personal success, has enjoyed his own successes both professional and personal and has always wished her well.”
Other defendants named in the case include the book’s co-author, Michaela Angela Davis, its publisher Macmillan, and the imprint Andy Cohen Books.
None of the parties had responded to the legal filing at the time of writing.