Lisa Rinna 'Real Housewives Of Beverly Hills:' Soap Star 'Made Threats' Against Kim Richards [VIDEO]

Lisa Rinna and Kim Richards engaged in a bitter fight during filming on the latest installment of The Real Housewives of Beverly Hills.

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According to a new report, Rinna and Richards got into it during a cast party hosted by Adrienne Maloof, who returned to the Bravo series after a season-long hiatus.

“All of a sudden out of nowhere, Lisa Rinna starts yelling and screaming at Kim…Lisa was furious with Kim about some perceived slight, and it QUICKLY got physical,” a source revealed to Radar Online on October 30. “Lisa attempted to push Kim, and the women had to be physically separated! Lisa even made threats against Kim. It was totally crazy.”

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Richards was seen struggling with an addiction to alcohol during the first two seasons of The Real Housewives of Beverly Hills, but luckily, after going to rehab to address her problem, Richards got sober.

Now, a source close to Richards claims she's still sober, despite recent rumors, but “is furious at producers for trying to insinuate she has suffered a setback in her recovery.” Earlier this week, Radar Online reported Richards' co-stars were questioning her sobriety after a group trip to Amsterdam, where Richards was accused of slurring her words.

Fans of The Real Housewives of Beverly Hills “will be shocked at how insane Adrienne’s party was,” the insider added. “It was exactly what producers had hoped for!”

Following season four, Kim Richards appeared on Bethenny, where she spoke about Lisa Vanderpump's phony friendship.