According to TMZ and Paris Jackson:

Katherine Jackson has been reported missing by her nephew late Saturday night ... law enforcement sources tell TMZ.

According to our sources, a nephew of Katherine's filed a missing person's report with the L.A. County Sheriff's Department after her grandchildren had been unable to reach her for over a week. 

Jermaine Jackson tweeted earlier this week that Katherine was in Arizona resting up on doctor's orders. But early this morning, Paris Jackson tweeted, "yes, my grandmother is missing. i haven't spoken with her in a week i want her home now."

She followed that up with a plea for people to call the authorities if they see her, then added, "the same doctor that testified on behalf of dr murray saying my father was a drug addict (a lie) is caring for my grandmother... just saying."

Katherine Jackson's lawyer told CNN she has never gone more than 24 hours without speaking to her grandchildren.

As TMZ previously reported, the Jackson family has been feuding of late ... with Randy, Jermaine, Tito, Rebbie and Janet Jackson seeking to have the executors of the Michael Jackson Estate resign from their positions.

A letter that leaked on the internet, written by the aforementioned Jacksons, claimed that John Branca and John McClain had "taken advantage of the family ... and have stressed out Katherine Jackson so much, that she recently suffered a "mini-stroke.'"