'Drugged' Katherine Jackson Demanded that Heads Roll

Katherine Jackson called her home in Calabasas at 2 AM today and again at 4 AM, sounding "drugged" and ordering that the security team be fired and replaced by Janet Jackson's security ... TMZ has learned.

A lawyer in court today made reference to "an incident" last night -- this is the incident. Sources involved in the situation tell TMZ ... people in the house were "alarmed and nervous" after hearing Katherine sounding heavily drugged.

In addition to attempting to 86 the security team, Katherine ordered Trent Jackson off the property. You may recall, Jackson's security -- and Trent in particular -- thwarted Monday's attempt by Randy, Jermaine and Janet to take the kids to Arizona.

Our sources say the prevailing view is that Randy and company have drugged their mom.

We're also told Jackie Jackson is furious at his conspiratorial siblings for what they've done and what they are trying to do.

We were unable to get Randy for comment.

Katherine's lawyer, Perry Sanders, tells TMZ ... "I'm waiting on Katherine to get back in town and I'm looking forward to getting a hold of her to ascertain what's been going on."

2:43 PM PT -- Randy Jackson has gone to Twitter ... claiming Katherine fired Trent and her security team at 9 PM last night ... NOT between 2AM and 4AM this morning.

He makes no reference to allegations she was "drugged up" during the phone call ... but Randy does say he was on the phone with Rebbie when it all went down.