The tweet has since been deleted, but referenced text messages she had sent him and a picture of a mystery woman.
"Since you won't reply to my texts I'm giving you an hour to tell the truth or I'll tell it for you," Cyrus' message said. The photo shows Cyrus with the woman posing together.
She later posted a tweet saying, "Wtf? My twitter was just actin all types of cray!", implying she had been hacked. The prior tweet was gone with no explanation.
Her mother Tish filed for divorce from Billy Ray on June 13 after 19 years of marriage, citing "irreconcilable differences." The tweet has stirred up rumors about the divorce, as the photo posted seems unlikely to be a hack. The photo has not surfaced elsewhere.