Jaime Pressly and Estella Warren's fun night out in L.A. turned ugly when police had to be called in after Pressly's assistant's phone went missing.

According to Us Weekly, the two women were enjoying a birthday party when Pressly's assistant told her that her phone was missing. Apparently the assistant's purse and phone went missing at the first party location, and using an app to locate her phone, Pressly and her assistant went to a second party location where Warren was also partying. That's when Pressly confronted Warren, accusing her of stealing the phone.

There was no physical altercation, but police were still called in to resolve the issue. A source told Us Weekly, "Jaime was trying to get it back. She wasn't aggressive, but she was forceful."

Things got messy after drugs were reportedly found in Warren's purse. "Jaime and her assistant were volunteering for a drug test. They said the drugs weren't theirs. It was this crazy mess," the source said.

The West Hollywood Sheriff's Department says the investigation is still active.

Last month, the 35 year-old actress got a headstart on the summer when she showed off a stunning bikini body while vacationing in Cancun with her new boyfriend, Hamzi Hijazi.