A nephew of Katherine Jackson reported the Jackson family matriarch missing late Saturday night after her grandchildren were unable to get in touch with her for a week.

It is the latest chapter in a messy dispute between several of Jackson's children and her advisers over her finances and legal affairs.

Jackson's nephew, Trent, filed the report with the Los Angeles County Sheriff's Office. But one of her sons involved in the dispute said she was fine and resting in Arizona.

"I want to reassure everyone (inc all sudden medical experts) that Mother is fine but is resting up in AZ on the orders of a doctor, not us," Jermaine Jackson tweeted.

"This is our mother and her health is paramount. We are not inventing or plotting anything. We are following doctor's advice. Period," he added.