Sydney  - Australian police said Friday they expected to press charges over an art exhibition in Sydney that featured nude photographs of children aged 12 and 13.

Acting on a complaint of child pornography being passed off as art by controversial photographer Bill Henson, police closed down the show on Friday and carted off more than half the 41 photographs.

The gallery also took down teaser photographs it had put on its website to create publicity for the exhibition.

"Police are investigating this matter and it's likely that we will proceed to prosecution on the offence of publishing an indecent article under the Crimes Act," Superintendent Allan Sicard told reporters outside the gallery.

He said the police inquiry included speaking to Henson, the 12-year-old girl featured full-frontal in the photos and her parents.

Hetty Johnston, executive director of child sexual assault action group Bravehearts, labelled Henson a pornographer and urged police to charge both him and the gallery showing his work.

"He's making money out of it, the gallery is making money out of it and the parents of the child are making money out of it," she told national broadcaster ABC.

Prime Minister Kevin Rudd agreed, describing the photos as "absolutely revolting."

Henson has hidden from the media, as has the gallery owner, but friends and supporters have fielded questions on their behalf.

"Bill's work isn't the problem here," art gallery curator Judy Annear said. "It's just a convenient kind of whipping boy at this particular moment in time."

She said people were wrong to accuse him of child abuse or child pornography and argued Henson was doing his duty as an artist by "pushing the boundaries" of what was permissible.

Clive Hamilton, the former head of Canberra-based think tank The Australian Institute, said the fact that the gallery had put selected photographs on the internet meant it could not hide behind the fiction that they were only intended for showing to a sophisticated art-house audience.

Hamilton said that while Hanson had an obligation as an artist to push the boundaries of what was acceptable, society also had a right to push back.

"If this girl at age 30 had a career and an integrity and a history behind her and suddenly these pictures were to pop up in a magazine or on the internet, I'd imagine there's a good chance that she'd be humiliated and yet it seems to me the adults around her ... were not fully aware of these dangers and have probably caused that child some damage." (dpa)