Brandi, 42, first made several guest appearances in the hit series during season two, and quickly became one of the most controversial stars, leading to an official spot on the show for season three.
The single mother of two became knowns for her excess drinking and wild nights out, in addition to starting drama between the ladies on the show.
"Bravo and production were over it and she basically became a liability. Believe or not, she became too toxic for the show and just didn't fit in any longer," a source close to the show told Dish.
"Brandi was told she was let go from the show nearly a week ago, and she's already freaking out. As much as she'd like to move on to her own venture, she really needs the Housewives money."
Brandi's ex-husband Eddie Cibrian left her in 2009 when an affair he was having with country singer LeAnn Rimes went public. The two officially divorced in 2010 and he would go on to marry LeAnn, and she and Brandi have been feuding ever since.
Another source exclusively tells Dish that pals are worried about Brandi now that she's lost her main source of income and think it could ultimately throw her into a downward spiral.
"She's been in a dark place for a while now, this was bound to happen. Friends are holding out hope that this might be her rock bottom," the insider dished.
"It was easy for Brandi to drink too much and cause drama on the show just to make sure she'd appear in most of the segments. Without that excuse, she's going to have to face herself in her every day life."
The network has yet to confirm Brandi's departure.