The former O.C. star has started legal proceedings against mum Nuala, accusing her of stealing money and making endorsement deals using Mischa's name, according to reports.
In a statement to People, a lawyer for Mischa said: "From the outset, Nuala positioned herself to siphon her daughter's hard-earned money by purportedly acting as her talent manager – a role for which Nuala had absolutely no experience or training."
Mischa, 29, began her career as a child actor in movies including The Sixth Sense and Notting Hill. She gained worldwide fame on teen drama The O.C., from 2003 until 2006.
According to reports, the legal papers filed by Mischa's attorney claim her mother now lives at a multi-million dollar Beverly Hills mansion, bought with Mischa's earnings, where the actress is not welcome to visit.
A lawyer for Mischa's mum told The Hollywood Reporter they had received no complaint yet and declined to comment.