Kim Zolciak called the cops on her estranged husband, Kroy Biermann, earlier this month -- and it was all because he allegedly accused Kim's friend of kidnapping their young son.
TMZ obtained audio from the 911 call Kim placed on June 16 in Alpharetta, GA. In her chat with the dispatcher, Kim says she's stressed out about her husband flipping out ... claiming he accused her friend of trying to kidnap their son.
The backstory is a little murky .