Mitt Romney's second cousin, Park Romney, once was once a Mormon high priest, but he is now denouncing the religion as a cult.
Park told BBC recently that he left the church because "I became convinced that it's a fraud."
"There's compelling evidence that the Mormon Church leaders knowingly and wilfully misrepresent the historical truth of their origins and of the church for the purpose of deceiving their members into a state of mind that renders them exploitable," he explained.
Park points to one of the Church of Jesus Christ of Latter-day Saint's foundational documents, the Book of Abraham, which church founder Joseph Smith claimed to have translated from an Egyptian scroll.
After examining the translation, British Assyriologist Dr. Archibald Henry Sayce determined that it was "difficult to deal with Joseph Smith's impudent fraud."
"His facsimile from the Book of Abraham No. 2 is an ordinary hypocephalus, but the hieroglyphics upon it have been copied to ignorantly that hardly one of them is correct," Sayce wrote.
London University's Dr. W. M. Flinders Petrie also agreed (PDF) "that there is not one single word that is true in these explanations."
But Harvard Kennedy School Prof. Robert Putnam told BBC that the former Massachusetts governor's religion is not often questioned in the U.S. because Americans value freedom of religion.
"It's not something you're supposed to talk about," Putnam said. "Whenever the issue of Romney's Mormonism has come to the surface, there's been lots of condemnation across the political spectrum for raising the issue of his religion."
"I'm not saying it's not relevant, but it's not talked about in polite company."
For his part, Park claimed that the church encouraged his family to "shun" him after he began to question their tenets.
"I am alienated from my family," Romney's second cousin remarked. "Their doctrine, their protocol and their culture as enforced by bishops encourages the families to disassociate themselves from the apostate."
Mormon Church elder Jeffrey Holland insisted that the church had no policy of shunning.
"We don't use that word and we don't know that practice," he said. "If that is what they believe, it's probably a good thing they leave, because we're not a cult."
"[I]f people want to call us a cult, you can call us a cult," Holland added. "But we are 14 million and growing."
Watch this video from Park Romney, uploaded to YouTube June 19, 2011.