Joanna Krupa

Catholic activists are criticizing a new PETA advertisement featuring model Joanna Krupa wearing only a crucifix, saying the ad "exploits Christian symbols."

"It's totally inappropriate," InsideCatholic.com Publisher Dean Hudson told Fox News. "It's another instance of disrespect toward Christianity and another example of the kind of abuse that would never occur with any other major religion, because the outcry would be so immediate and so loud that the people behind it would immediately retreat."

Joanna Krupa exceeded her Dancing expectations, "proud" of Playboy cover

The ad is specifically designed to encourage would-be pet owners to adopt from pet shelters rather than pet stores. Catholic League President Bill Donohue said in a statement that Krupa's new ad by the People for the Ethical Treatment of Animals "exploits Christian symbols ... The fact is that cats and dogs are a lot safer in pet stores than they are in the hands of PETA employees. Moreover, pet stores don't rip off Christian iconography and engage in cheap irreligious scams," Donohue said.

Krupa, 30, responded to mounting criticism. "As a practicing Catholic, I am shocked that the Catholic League is speaking out against my PETA ads, which I am very proud of," Krupa said. "I'm doing what the Catholic Church should be doing, working to stop senseless suffering of animals, the most defenseless of god's creation."

Dancing's Joanna Krupa: "People will see the real me"

A contestant on this past season of Dancing with the Stars, Krupa also appeared in a slightly more covered-up ad for PETA in early November. However, it seems Catholic League has a broader gripe with organization behind the racy photo.

"PETA is a fraud. It also has a long and disgraceful record of exploiting Christian and Jewish themes to hawk its ugly services," Donohue said. "Those who support this organization sorely need a reality check. They also need a course in Ethics 101."