9:30 AM PT -- According to Manhattan Beach PD, Vaughn and his passenger were stopped at the checkpoint around 12:30 AM, and asked to step out of the vehicle. Cops say both men were uncooperative and, initially, refused to get out.
Once they did, Vaughn was arrested around 1 AM and booked and cited for misdemeanor DUI, as well as obstructing an officer. His passenger was booked for obstruction and public intoxication.
Both men posted bail and have been released.
According to law enforcement, the actor was booked into jail around 4 AM Sunday in Manhattan Beach, CA -- about 30 minutes south of Los Angeles.
We're told Vaughn is still in custody right now. The details of his arrest are still unclear, but according to a source ... he was stopped at a checkpoint while driving with a passenger in his car.
If charged, this would be Vaughn's first DUI offense.
We've reached out to his reps ... no word back yet.