LOS ANGELES, USA (AP) - Authorities said today they believe Katherine Jackson, the mother of Michael Jackson and the guardian of his three minor children, is safe in Arizona with family members after she was reported missing.

The disclosure came after another concerned family member officially reported her missing Saturday night amid a dispute over the estate of her superstar son.

The Los Angeles County Sheriff's Department was still trying to speak with Katherine Jackson but said she reportedly is with other relatives.

Paris Jackson, the 14-year-old daughter of the late legend, tweeted early today that her grandmother was missing.

"I haven't spoken with her in a week I want her home now," she posted from her Twitter account. She also tweeted a number for people to contact in case they saw the 82-year-old matriarch of the famous singing clan.

The family drama unfolded days after it was revealed that some of Katherine Jackson's children had written a letter to the executors of Michael Jackson's estate, alleging his will, which left his fortune to his children, his mother and charity, was a fake.

The undated letter, signed by Janet, Randy, Tito, Rebbie and Jermaine Jackson, claimed Katherine Jackson was being manipulated by the executors, John Branca and John McClain, her health had been affected, and she suffered a mini-stroke.

The legitimacy of the letter was confirmed by Randy Jackson on Twitter, and Janet Jackson retweeted his post.

The estate has denied the accusations.

Paris Jackson lashed out at her uncle Randy Jackson on Twitter, saying her grandmother was fine.

"I will defend my beloved family member with all I have, even if it means from other family members," the tweet said.

She later apologised, saying she just wanted to let people know that her grandmother did not have a stroke.

Katherine Jackson's attorney Perry Sanders Jr said Friday that his client did not have a stroke, according to his interactions with her and with her relatives. Sanders could not immediately be reached for comment.

On Friday, Jermaine Jackson tweeted that his mother was resting on the orders of a doctor in Arizona.

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

Conrad Murray was convicted of involuntary manslaughter for the June 2009 propofol overdose death of Jackson at age 50.

Katherine Jackson has been caring for Paris, Prince Michael and Blanket Jackson since their father's death. It was unclear who is taking care of the children in her absence.