The text exchange came three hours after Janet Jackson was seen on security camera video apparently attempting to take Paris Jackson's cell phone away in the driveway of Katherine Jackson's home. Janet Jackson's representative did not immediately reply to CNN's request for comment.
Prince's Twitter posting referred to words of caution from his father.
"As long as I can remember my dad had repeatedly warned me of certain people and their ways," he tweeted.
The tweet concluded, "If you continue with your lies I will continue with the truth." It was signed "Michael Jackson Jr."
The tweets mysteriously disappeared several hours later, replaced with a message disavowing them. That message subsequently vanished and was replaced by another saying Prince didn't know if his account had been "hacked."
He then reposted the original message about his grandmother and the image of the text exchange.
Before Katherine Jackson began the long drive back to California on Wednesday, she appeared on camera and read a statement to ABC News.
As her children Rebbie, Jermaine and Janet stood behind her, she read from a yellow notepad:
"I am devastated that while I've been away ... my grandchildren have been taken away from me, and I'm coming home to see about that," Jackson said. The network was not allowed to ask her any questions.