The Carnegie Science Center and its supporters describe "Bodies ... The Exhibition" as an educational experience, capable of persuading visitors to quit smoking, live healthier and consider organ donation.

But the controversial exhibit's vocal opponents -- represented by religious leaders and medical and bioethicists -- see the popular attraction as an exploitative display pandering to lurid curiosity.

With new questions about the origins of the bodies as a backdrop, proponents of both viewpoints participated in a panel discussion last night hosted by WQED-TV as a special expanded edition of "On Q." It was broadcast live from 7:30 to 9 p.m.

A studio audience of 25 saw a panel that included ethicists, clergy, law enforcement officials and Carnegie Science Center Director Joanna E. Haas.

A Feb. 15 segment on ABC's "20/20" reported that the specimens displayed in "Bodies ... The Exhibition" are the cadavers of Chinese prisoners purchased on the black market.

The company behind the bodies display, Atlanta-based Premier Exhibitions, denounced the report, yet it has persisted in raising more questions about the ethics of the exhibit, on display in Pittsburgh since early October.

Some members of the panel, such as Allegheny County medical examiner Karl Williams and Duquesne business ethics professor Jim Weber, believe exhibits like "Bodies" and the use of human bodies for science in general have value, provided they are legally obtained.

"I deal with bodies on a daily basis, and I use them for an education purpose," Dr. Williams said.

Even before the "20/20" report, some local religious groups opposed the exhibit at the Science Center, calling it an undignified display of the deceased, stripped of their humanity for a profit-driven enterprise. Science center officials said they have several sworn affidavits from Premier Exhibitions stating the bodies were unclaimed remains that were obtained legally.

But even that scenario would raise ethical questions, said Rabbi Danny Schiff, one of the panelists.

"There seems to be a presumption that if you have unclaimed bodies you have carte blanche to do whatever you please with them," he said. "In their lifetime, some of these people might have been horrified by being put on display like this."

One science center employee, Education Coordinator Elaine Catz, decided to quit her job, citing religious objections to the exhibit.

But most of the museum's staff and an advisory committee formed to examine the ethical concerns with the exhibit believe in the benefits of showing the attraction, said Ms. Haas.

Numerous visitors agree, some leaving post-it notes on a wall near the exit expressing their positive impression, Ms, Haas said.

"We knew this exhibit would carry controversy," she said, but the science center has done its due diligence in taking ethics into consideration, even calling a special meeting of its advisory committee after the "20/20" segment aired.

"I think Carnegie may have done due diligence," said panelist Alan Meisel, a bioethics expert at the University of Pittsburgh. "But I think they are relying on an organization that is not."

The bodies are preserved by a process called plasticization, which replaces the body's natural water with polymers. The 15 specimens at the Carnegie Science Center have been dissected and separated by organ system, showing the respiratory, digestive, nervous and other tissues individually.

The exhibit will remain at the Carnegie Science Center until May 4.