Lopez, 42, maintains that Hakob Manoukian, who was in charge of her security and transportation, engaged in extortion, attempted extortion and conspiracy.

Manoukian, who started working for the star in 2005, has also been clashing with her manager, Benny Medina, over alleged contractual differences.

Lopez alleges that Manoukian wanted more money and additional control of her security team. She is seeking $20 million in damages, the documents filed in Los Angeles Superior Court show.

"Manoukian plotted to retaliate against Ms. Lopez and her management and to use his apparent position of trust to exploit and extort substantial sums from Ms. Lopez," the lawsuit reads in part.

"In the furtherance of this plot, he abruptly terminated his employment with Ms. Lopez and began to threaten her" with revealing "sensitive and personal information that he had allegedly overheard while driving Ms. Lopez."

On July 13, Lopez announced she was quitting ratings-challenged TV talent show American Idol, a day after fellow judge Steven Tyler announced his departure.

She is also singing on tour with co-headliner Enrique Iglesias.