But the law change may threaten artists who do not get their work classified by Commonwealth censors. The artist Bill Henson had his contentious work judged by film censors before going to exhibition.

The artist Polixeni Papapetrou, whose photograph of her six-year-old daughter on the cover of Art Monthly caused a storm last year, did not have her work sent to censors.

She criticised the law change yesterday and asked whether she could be prosecuted if her work were judged by authorities as child pornography, saying: ''I think they're barking up the wrong tree. I really think they should be going after those people who exploit children.

''I don't know of any artists who exploit children and if they do they should not be protected by any legal defence.''

The law change received cautious support from the executive director of the National Association for Visual Arts, Tamara Winikoff, who said artists were working with the director of public prosecutions on ''protective protocols so that art experts are consulted and can advise on whether the material had been produced by a genuine artist''.