Bale 'a dream' to work with

'Public Enemies' director Michael Mann insists Christian Bale - who has been described as "intense" by several former co-stars - was the perfect person to take on the role of detective Melvin Purvis in his latest movie.

Mann said: "He was a dream - he really was a dream to work with. He is a good guy and a great actor.

"Every actor is different but Christian immerses himself completely in the role. He dives into the deep end of the swimming pool and he is there the whole time.

"The character of Melvin Purvis is really interesting. He was a member of the gentry who settled in America in the 1600s. Those families were from the richer southern counties of England and they got the best land - Virginia and South Carolina. He was a very rigid young man, with very specific traits and codes. He breaches those codes when goes to work for J. Edgar Hoover and begins persecuting the innocent and using torture.

"I had to have someone who embraced those values and Christian clearly was that man."

Mann has also spoken about how Christian was so devoted to the role, he drove his young daughter "nuts".

He added: "When he perfected the accent he changed his whole way of talking all the time.

He would talk with a genteel Southern accent and it drove his three-year-old daughter nuts. She would say, Daddy, stop talking like that.' And he would say, 'My darling I have to talk like this to play Melvin Purvis and I will be doing so until the film has finished shooting.' "