Whitney Houston returns to rehab

LOS ANGELES, May 9 (UPI) -- Whitney Houston's publicist says the U.S. pop star has voluntarily enrolled in an out-patient treatment program for drug and alcohol addiction.

The "I Will Always Love You" singer's representative told TMZ the decision to enroll in the program 10 days ago is part of Houston's "longstanding " recovery process.

The Grammy Award winner's substance-abuse issues and erratic behavior sidelined her once-bright career for more than a decade.

She re-emerged into the spotlight in 2009 with the album, "I Look to You." She has since worked to stay sober and has managed to avoid public scandal.

However, TMZ quoted a music industry source as saying the recording artist suffered a relapse two weeks ago.

"She was plastered and she was a mess," the unnamed insider said.