The London police are discreetly addressing the press by stating that "A 34-year-old man attended a central London police station this morning by appointment and was arrested in connection with an allegation of assault. He currently remains in custody."
“Christian Bale attended a London police station today, on a voluntary basis, in order to assist with an allegation that had been made against him to the police by his mother and sister,” the actor’s reps said in the statement. “Mr. Bale who denies the allegation, co-operated throughout, gave his account in full of the events in question, and has left the station without any charge being made against him by the police. At this time, there will be no further comment by Mr. Bale.”
and TMZ is reporting rumors that the accusations were for *verbal* assault.