Abuse! Abandonment! Forced imprisonment! Those are just some of the ugly charges being hurled by Janet Jackson and her estranged husband, Qatari billionaire Wissam Al Mana, in their $250 million divorce battle, Breaking Celebrity News has learned exclusively!

"They're officially at war!" tattled a Jackson family insider.

"Nasty" singer Janet, 51, fled their five-year marriage in April amid talk the controlling Muslim businessman had dominated her life and cut her off from her famous family.

Janet has told mediators Wissam's abuse was so brutal she wants full custody of their ten-month-old son, Eissa — with only limited visitation for Wissam.

But Wissam, 42, is charging he was the one who was abused — and that Janet slammed his abilities as both a husband and father!

When the couple's mediation picks up in London in December, Wissam plans to "bring in his family and at least two housekeepers who are willing to testify it was Janet who was vicious with her tongue!" the source revealed.

"She'd throw fits around the house, and complain about being imprisoned and shut off from the world."

Wissam is also telling his legal team Janet belittled her younger husband for taking so long to get her pregnant!

Wissam is also furious Janet constantly called her ex-boyfriend, rap producer Jermaine Dupri.

"She'd make sure Wissam heard her refer to Jermaine as baby or sweetie," the source said.

Insiders added Wissam would respond by fleeing the couple's London pad with a personal harem and host events with the sexy young vixens by his side.