Erin, best known for her title role in the 1988 movie "The New Adventures of Pippi Longstocking," was arrested Thursday on suspicion of assault, the Contra Costa Times of Walnut Creek, Calif., reported.
Erin was placed under citizen's arrest by her roommate, a man whose name was not released, after the two began fighting shortly after a pizza was delivered to their apartment, Walnut Creek police said.
Officers said they were not sure what caused the fight, but a neighbor called the police after hearing Erin's roommate call for help.
Erin was booked into the county jail and was released Friday morning.
In a Twitter response for comment, Erin tweeted: "100% Lies. You should be ashamed of lying."
That message has since been deleted.
No other details on the incident were reported.