Actress Lindsay Lohan confirmed on Friday that she had failed a court-ordered drug test a few weeks after being released from jail and going through a rehabilitation programme.
Lohan, whose career has been derailed by drunken driving and drug possession charges and a reputation for erratic behavior, posted a series of messages on her Twitter page that confirmed media reports of recent drug use.
"Regrettably, I did in fact fail my most recent drug test," she wrote.
"... Substance abuse is a disease, which unfortunately doesn't go away over night. I am working hard to overcome it and am taking positive steps forward every day. I am testing every single day and doing what I must do to prevent any mishaps in the future."
Celebrity news site TMZ.com said the "Mean Girls" actress had tested positive for cocaine last week. Under the terms of probation set in August, Lohan would be sent back to jail for 30 days if the reports prove correct.
Before her admission, Us Weekly magazine's website quoted Lohan Friday as saying "I'm fine. They're all nuts."
Lohan said on Twitter that she was prepared to return to court and "face the consequences."
Lohan went to rehab three times in 2007, the year she was charged with drunken driving and cocaine possession.
After violating her probation in the 2007 case, Lohan served two weeks in jail in August, followed by 22 days of a three-month residential drug rehab program.
On her release she was ordered to undergo random testing twice a week and attend drug counseling and behavioral therapy classes.