Mariah Carey's Former Manager is Claiming Sexual Harassment

Mariah Carey's former manager claims she was repeatedly sexually harassed by the singer, because Mariah was constantly naked in front of her ... TMZ has learned, but Mariah calls the allegation "baseless."

We broke the story ... Stella Stolper filed docs putting Carey's team on notice a lawsuit is coming, and now we know what's behind it all. We're told Stella is claiming Mariah rarely wore clothes around her, and was not only naked ... but did sexual things in Stella's presence.

We're told Stella will also allege Mariah has a substance abuse problem, and fails to take her meds for bipolar disorder. Just last week, Mariah revealed she was diagnosed with bipolar disorder in 2001 ... but Stella's claiming that's just a small part of her problems.

Further, Stella will claim she was unfairly fired in the middle of her 3-year contract, and is still due a ton of cash. She's giving Mariah an opportunity to make things right, before the lawsuit is filed.