Katherine Jackson knows exactly what's going on with the guardianship situation, and we're told by a family source, she's "infuriated." She's dismissing claims that she has been drugged by family members ... calling those online reports "total lies."

The 82-year-old Jackson matriarch, who we're told "cried" while watching the video of the confrontation outside her home between her family members, has fired her nephew Trent Jackson, as well as the entire security team at her Calabasas home.

Contrary to claims that Katherine Jackson fired Trent and the team in the middle of the night, we're told the call was placed before 10pm Tuesday night.

Our Jackson source tells X17 exclusively that Trent and the security members refused to leave after her request ... telling Mrs. Jackson, "We don't work for you, we work for the estate. We're not leaving."

Katherine replied, "How dare you deny my children access to their home, to my home. My home is their home."

Michael Jackson's mom also "became enraged" with Trent and the security team "for putting their hands on my children."

As X17 exclusively reported Tuesday, our Jackson family source confirmed that family advisor John Branca was behind the confrontation on Monday at the Jackson estate between Janet, Randy, Jermaine, Paris, Prince, Trent and the security team.

We're told Branca "is trying to paint a picture that under Katherine's supervision, the kids aren't being cared for." Today, in court, TJ Jackson (Tito's son) was granted temporary custody of Michael's three children ... Paris, Prince and Blanket. Family members believe TJ, as well, has been coached by Branca.

Following Monday night's altercation at the Jackson compound in Calabasas, estate executors John Branca and John McClain, released the following statement:

    "We are concerned that we do what we can to protect them from undue influences, bullying, greed, and other unfortunate circumstances. While we do not have standing to directly intervene, we have monitored the situation and will continue to do so. We believe measures are being put in place that will help protect them from what they are having to deal with."

Katherine's attorney, Perry Sanders Jr, said in a press conference following the hearing that once Katherine gets settled back in LA, he'll be filing papers for her to be reinstated as the guardian of the three kids.

X17 broke the story Monday that Katherine's nephew Trent, as well as estate executors [for Michael Jackson's estate] John Branca and John McClain, and Jackson family advisors Lowell Henry and Perry Sanders, Jr., are being investigated for elder abuse against Katherine Jackson.

Despite the fact that LA Country Sheriff's spokesperson Steve Whitmore has denied there's an investigation into the elder abuse claims, Jackson family members confirm that the Sheriff's Dept. is involved in the case.