People.com reported O'Neal, 26, was taken into police custody Thursday after he confessed he used narcotics while in a court-ordered rehabilitation facility where he was serving a year sentence on separate drug and weapons charges.
He is to be sentenced Oct. 7 for his latest transgression.
"This morning Redmond admitted to a violation of using methamphetamines while on probation," People.com quoted O'Neal attorney Mike Brewer as saying. "There is no guarantee what Redmond's new sentence will be."
2014: The Year in Music [PHOTOS]