JOHANNESBURG, South Africa (AP) _ A regional attorney-general said Thursday the movie, ''Cry Freedom,'' may violate the law if it is shown in movie theaters, even though government censors approved it without cuts.

Klaus von Lieres, attorney-general for the Witwatersrand region, which includes Johannesburg, was quoted by The Star newspaper as saying the Internal Security Act makes it illegal to publish or disseminate views purporting to be those of a banned person, someone who cannot legally be quoted in South Africa.

The movie is about the friendship between Black Consciousness leader Steve Biko and Donald Woods, a white South African newspaper editor who was banned before he fled the country.

Von Lieres said the Internal Security Act was ''quite broad'' and the fact that Woods' views are being disseminated by an actor ''makes an enormous difference.'' But he said the Publications Appeals Board's approval of the film for showing in South Africa made no difference in determining whether it violates the Internal Security Act.

Earlier in the week, von Lieres had said he would consider prosecuting newspapers which carried advertisements for the movie. The ads quote lines from the movie in which Woods says of Biko: ''I don't understand why he is banned. You need a black leader you can talk to.''

Biko was banned during his lifetime.

Peter Dignan, managing director of UIP-Warner, which is planning to distribute the film in South Africa in April, was quoted as saying he was ''surprised and astonished by what has arisen,'' and that the company still inteded to relase the film ''as broadly as possible.''

''We believe the public wants to see this film,'' he said.