Katherine Jackson has been reported missing.

The Los Angeles County Sheriff's Department were contacted after her grandchildren, Paris, Prince, and Blanket were unable to reach her all week.

Lt. Josh Thai from the police department confirmed that the mother of late superstar Michael Jackson was indeed not responding to pleas from her family.

"I can confirm that a missing person's report was filed this evening by Mrs. Katherine Jackson's nephew, Trent Jackson, after he was unable to see her or reach her for a week. The report will be referred to the Homicide/Missing Persons Unit, and they will be handling the investigation," he told US website Radar Online.

A source added that the family are concerned for Katherine's welfare.

"The kids are being taken care of by their nanny. Paris is absolutely beside herself with worry. She lost her father three years ago, and not to know if her grandmother is ok is just more than she can bear," the insider revealed.

Katherine, 82, left her California home on July 15 to fly to New Mexico with her oldest daughter Rebbie Jackson, her lawyer Sandra Ribera told CNN.

"The kids were trying to get a hold of their grandmother and they haven't been able to reach her for almost a week," Ribera said. "They are told she's unavailable. I'm concerned that she's not safe."