The actress was stopped for speeding on the 101 freeway in the San Fernando Valley, California.
According to a police report, obtained by news show Entertainment Tonight, officers also noted Fox was "unable to maintain lane position" in her Cadillac.
Police asked the actress to perform a field sobriety test, during which Fox was "unable to satisfactorily perform" and they noted that "a breath test indicated the presence of alcohol greater than 0.08%, the California legal limit."
She was released from police custody early yesterday morning.
Fox's publicist has refused to comment about the incident.
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