Truth about Romney-from Australia....

Bob Gay, her father, could have expected no more than commiseration. Instead, Mr Romney shut down Bain Capital, the $1 billion private equity business he led in Boston, and sent 56 employees to scour New York. He persuaded hundreds more financial workers to join the search and walked the streets himself. "I don't care how long it takes. We're going to find her," he pledged.

The Republican presidential candidate, who is now worth an estimated $US230 million ($226m), shrugged off his decision to mothball Bain Capital. "Money is just money," he said.

The story illuminates a character trait that could be a mighty electoral asset, but which he seems reluctant to highlight. It also brings into play an issue that Mr Romney would rather ignore, but which could still prove pivotal in November's election and is perhaps his most definitive feature: his Mormon faith.

Mr Romney later described quizzing New York's runaways for clues of her whereabouts. "It was a shocker," he said. "The number of lost souls was astounding."

The search was just one of many good deeds. A recent biography, The Real Romney, described how, during his first foray into politics - a failed challenge to Ted Kennedy, the late Massachusetts senator, in 1994 - he took a day off to help a single mother to move house. During the same campaign, after learning that a veterans' shelter was struggling, he began paying part of its grocery bill. The donations were kept secret.

Similar stories abound. "It seems that everyone who has known him has a tale of his altruism," said Scott Helman, one of the book's co-authors.

The anecdotes often go beyond the signing of a cheque. In 1986, he helped to build a playground in memory of a neighbour's 12-year-old son who had died of cystic fibrosis. "There he was with a hammer in his belt, the Mitt nobody sees," the boy's father, Joseph O'Donnell, said.

One obvious question, then, is why are glimpses of this Mr Romney so rare on the campaign trail?

The Melissa story has been cited in adverts but remains little-known. Other kindnesses have never been mentioned. According to David Frum, a conservative commentator: "Voters are likely to know two things about Mitt Romney: that he's rich and that he's a Mormon."

That two-dimensional profile has helped the Obama team to cast him as irredeemably patrician and coldly calculating; detached from ordinary Americans by his wealth and privileged upbringing. His reluctance to rebut that characterisation seems to involve his deeply rooted faith.

History, doctrine and modern-day polling suggest that the search for Melissa was a typically Mormon mission. In the 19th century, Mormons escaped persecution by fleeing to what is now Utah. The desert terrain was hostile; the wagon-trail unforgiving. A tradition of community endured. A recent survey showed that nearly three-quarters of followers believe that working to help the poor was "essential to being a good Mormon".

Another found that the average church-going Mormon spent 430 hours a year volunteering - nine times as many as the average American. Another report showed that the US's most charitable households were in Salt Lake City, the epicentre of Mormonism.

Michael Otterson, the head of the church's press department, explained such statistics by citing the Mormon idea "that mortal life is a test, or probationary period in our eternal progression". Mormons believe, quite literally, that they are saints, and strive to act accordingly, he said.

All of this might bode well for Mr Romney's political ambitions, were it not that Mormons are still regarded with suspicion.

The faith's history of polygamy is often mocked. Its opposition to gay marriage is branded homophobic by liberals, while some evangelical Christians, the bedrock of the Republican base, regard Mormonism as heretical. Nearly half of Mormons say that there is "a lot of discrimination in the United States" against them while one-fifth of Americans say that they would not vote for a Mormon for president.

"(Mr Romney's) altruism is closely connected to his Mormonism," said Andrea Butler, a professor of religious studies at the University of Pennsylvania. "And that helps explain why he can't capitalise on it." There is also the story behind Mormonism. Joseph Smith, its founder, claimed to have translated its central scripture from a set of golden tablets he discovered in 1827. This was done using a pair of supernatural spectacles, he said.

Incredible stories are, as Kathleen Flake, a professor of American religious history at Vanderbilt University, in Nashville, says, "the stuff that religion is made of".

Perhaps it is understandable that Mr Romney would rather his faith go unmentioned. Even if it means his good deeds go unnoticed.