AceShowbiz -

Janet Jackson's split from Wissam Al Mana turns nasty as they're now embroiled in legal battle over their son, 10-month-old Eissa. The 51-year-old singer and her billionaire estranged husband are "officially at war," a Jackson family insider told Radar Online.

Janet ended her five-year marriage to Wissam in April allegedly due to the Qatari businessman being controlling, having dominated her life and cut her off from her famous family. According to the news outlet, Janet has told mediators Wissam's abuse was so brutal she wants full custody of their son, with only limited visitation for Wissam.

But Wissam is insisting that he was the one being abused and that Janet "slammed his abilities as both a husband and father." When the estranged couple's mediation picks up in London next month, Wissam allegedly 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!" revealed the source.

"She'd throw fits around the house, and complain about being imprisoned and shut off from the world," the source said of Janet's supposed behavior during her marriage to Wissam.

Wissam is also said telling his legal team that Janet "belittled" him for taking so long to get her pregnant. In addition, the 42-year-old businessman is furious Janet allegedly constantly called her ex-boyfriend, music producer Jermaine Dupri.

"She'd make sure Wissam heard her refer to Jermaine as baby or sweetie," according to the source. Wissam allegedly would respond by fleeing their then London pad "with a personal harem and host events with the sexy young vixens by his side."

And Janet allegedly got revenge on her then husband in the best way possible. "Janet would hear about the other women from their security detail and other staffers, and then she'd take her game up a notch," the source said. "She'd shower, oil her body and walk past Wissam in the nude before throwing on a robe, but "when he would try to come on to her, she'd say 'no,' and tell him to 'handle that yourself.' It made him furious!"

"Wissam has a quiet way about him that can make people believe he's a cool, calm, collected guy. But he has a lot more fight in him than you might think," the insider added.