UPDATE: Kelly was seen partying at a pre-Golden Globes event -- The Art of Elysium on Saturday night -- not a post-Golden Globes event as first reported.
After nearly three years of sobriety, Kelly Osbourne has fallen off the wagon and is back to boozing, RadarOnline.com has exclusively learned.
The 27-year-old daughter of Sharon and Ozzy Osbourne got clean in February of 2009 after completing a rehab stint for drug and alcohol addiction, but according to several sources the fashionista is back on the bottle.
"Kelly is definitely off the wagon again -- at least when it comes to drinking," an insider tells RadarOnline.com. “I’ve seen her out drinking cocktails, beer and champagne numerous times, and I’ve seen her pretty unsteady on her feet too."
And just this past Saturday night, Kelly guzzled cocktails at The Art of Elysium event at Union Station and got so wasted (as evidenced by the exclusive photo) that she almost fell over.
"Kelly was so wasted," an eyewitness who partied with the Fashion Police host tells RadarOnline.com. "At one point she almost fell back and I had to catch her!"
According to the party pal, once Kelly gets alcohol in her system the claws come out in full force and she doesn't hold back about her constant feuding with Christina Aguilera.
"When she gets drinking her hatred for Christina Aguilera really comes out," the source said. "She spent the entire night talking about how much she hates Christina!"
The outspoken Brit and Christina have been battling for years, most recently with the newly slimmed-down Kelly poking fun at the Dirty singer's curvy new figure.
And in September Kelly ranted about Christina's bullying saying, "She called me fat for so many f***ing years. So you know what? F**k you! You're fat too."
"This is the side of Kelly that comes out when she's drinking," one of the sources told RadarOnline.com.
“Maybe she thinks it’s OK for her to be drinking as her past problems were pills, but as far as I know if you want to be ‘sober’ you need to be SOBER, period.”
Attempts to reach Kelly's rep for comment were unsuccessful at time of publication.