UPDATE 4-Batman star Bale denies family's assault allegation

(Adds comment from Warner Bros; details, updates box office)

By Mike Collett-White

LONDON, July 22 (Reuters) - Actor Christian Bale, star of the new Batman movie "The Dark Knight," on Tuesday denied allegations of assault made by his mother and sister after he was questioned by London police.

The Welsh-born performer, 34, riding high as Hollywood's latest blockbuster film star, spent several hours at a London police station before being released without charge, his Los Angeles-based spokeswoman, Jennifer Allen, said.

"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," Allen said in a 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."

She confirmed separately that the allegation was of assault, but said she knew no further details.

When asked if Bale had been arrested and released on bail, a police spokeswoman said: "A 34-year-old man has been bailed to return to a police station on a date in September." The wording is the usual tangential way British police have of confirming news about well-known personalities.

British media reports said Bale was arrested following allegations of assault made by his mother and sister in relation to an incident at his London hotel suite late Sunday.