Mariah Carey. Picture: AP

Mariah Carey is suing her former personal assistant for more than $3 million (about R41 million) after accusing the ex-staff member of trying to blackmail her.

The 'Hero' hitmaker has accused Lianna Azarian - who she hired in March 2015 but fired in November 2017 - of secretly recording her doing "embarrassing" things and then threatening to release the videos unless her famous boss gave her $8 million (about R109 million).

According to legal documents obtained by TMZ, Mariah claims Lianna was secretly filming her "personal activities" and if the clips were made public, they could be extremely damaging to her, both personally and professionally.

The 48-year-old singer paid the employee up to $327,000 a year until she was fired, and claims the alleged blackmail started shortly afterwards.

After previously showing the videos to friends and claiming she would sell them if she was ever fired, Liana reportedly demanded the money and warned she'd release the videos and other damaging information once she was dismissed.

The lawsuit doesn't state what is on the videos, but describes the footage as "intimate".

As well as recording the clips, the 'Fantasy' singer also alleged her former staff member used her credit card to buy personal items and obtained discounts from retailers by claiming she was buying things for Mariah.

The 'One Sweet Day' hitmaker - who has twins Moroccan and Monroe, seven, with ex-husband Nick Cannon - claims to have unsuccessfully demanded the videos and other evidence of criminal activity be handed over.

She is suing for unspecified damages, but she wants more than $3 million.

The new lawsuit comes just weeks after Mariah settled another legal dispute with her former manager Stella Bulochnikov, who took action against the singer last April, alleging she was owed millions of dollars.

An attorney confirmed recently: "The parties [have] reached a mutually agreed resolution to this matter."

The attorney declined to say whether their client, who had sought unspecified damages, had received a cash settlement.

Stella agreed to "discontinue this action against Mariah Carey with prejudice, with each party to bear its own attorneys' fees and costs."

Stella had previously said she was suing for breach of contract, violation of the U.S. Civil Rights Act, and a violation of the Fair Employment and Housing Act as she believed she was owed commissions on Mariah's earnings, with sources claiming the figure was more than $100 million in three years.