Elissa Wall is no longer the star prosecution witness against the cult leader Warren Jeffs and has come out of formal FBI witness protection, but she remains guarded about her whereabouts. Who knows what some devout supporter of Jeffs might do? Say she lives "somewhere in Utah". That's near enough.

We meet at a hospital where her husband, her true husband, the man she loves and chose to marry, Lamont Barlow, is being treated for a lymphatic disorder.

She is blonde and bright and welcoming. But the tears well when she reflects on life in the fundamentalist Mormon sect that made her an unwilling 14-year-old bride to her first cousin, Allen Steed, five years her senior. Jeffs, 52, was sentenced last November for facilitating her rape when he ordered Steed to consummate the forced marriage.

Jeffs, the sect prophet, claimed he was acting on a revelation from God when he directed Wall to marry Steed. She thinks it was mere vindictiveness, a malicious assertion of his power over members of the enthusiastically polygamous Fundamentalist Church of Latter Day Saints. She had, after all, defied this self-proclaimed messenger of God, telling him more than once she was not ready to marry.

"Especially after the way I stood up to him he thought, 'How can I punish her forever?' " says Wall, 22. "I think he saw that I did not want to marry [Steed] so that's exactly what he wanted me to do. In the beginning [the marriage] was so traumatising I didn't know what to do. I was still a child mentally, physically and emotionally, and I was not prepared for the responsibility of being a wife, or being forced to be a wife.

"Part of me could not wait for the end of the world to come and end this pain I was in. I had no love for Allen and he hurt me so deeply and so much. My marriage was a slap in the face and I should have been able to wake up sooner, but I had been so deeply conditioned to believe this was what I was supposed to do. I only had a sense of the reality that they gave me."

The episode climaxed last November when Wall's evidence of Steed's abuse fostered by Jeffs' instructions, helped jail the "prophet" for 10 years.

The cost, however, is not Jeffs' alone. Wall lost too: friendships, contact with much of her family, including her biological mother, and months spent shifting to secret addresses as a secured witness.

"I have not been able to have any contact with my mother in, wow, a little over three years," she says, surprising herself at the realisation.

"She tried to contact me during Warren's trial. I knew why she was trying to contact me and I knew from past experience that what the [church does] very well is use your family against you. They use your heart against you. I could not speak to her because I did not know if I would be strong enough. I didn't know if I could stand her pleas to not [testify]."

Jeffs escaped prosecution in a similar case in Arizona, she says, when girls who were to testify against him succumbed to sect pressure to withdraw.

"I kind of expected it," Wall says of her mother's "reaching out" to her. "I have to know that it's not her, that she's only doing it because there's somebody watching her, or because she feels like she has to. I have to hold on to the hope that she was not acting on her own. Otherwise it's too hard; it's too deep to think that after everything she watched me go through, she could not support me in that.

"Then I understand what it's like from her point of view. To believe so deeply in Warren to such an extent where you can abandon your own family because they told you to."

Wall is scarred deeply.

The mainstream Mormon church abandoned polygamy in 1890. However, the church maintains across the road from the Tabernacle in Salt Lake City one of the world's biggest genealogical databases where it promises to help visitors trace family trees.

The Fundamentalist Church of Latter Day Saints remains committed to polygamy and comprises a tangled web of intrafamily marriage and breeding among 13,000 followers in two adjoining towns on the Utah-Arizona border. There is another settlement at Yearning for Zion, the ranch at El Dorado, Texas, where child protection authorities this year conducted raids in pursuit of sex abuse claims.

Little about Jeffs' appearance - certainly not the scrawny physique and rodent features - suggests a command of respect and loyalty. Nor his character. By Wall's account, he is sexually prurient, inclined to prying into the activities of pubescent boys and girls, and adults. He is domineering and manipulative, making and breaking families at will.

Wall's father had 24 children by three wives. She was born to the second, who left her father for another man, all at Jeffs' instruction. The third wife, too, was ordered to separate from him, and turned up - with two of Wall's half-brothers - in the Yearn for Zion ranch raid. The father now lives with his first wife.

Jeffs has 143 wives, Wall believes. He "inherited" 34 of them from his deceased father, Rulon, who preceded him as prophet and kept about 60 wives. Two Wall sisters - one 22 at the time, the other 19 - married Rulon Jeffs when he was 83 and 86 respectively. Had Warren Jeffs consummated all 143 unions? "I don't know," says Wall, "but I would not be surprised if he has."

Wall witnessed the younger Jeffs grow in the role. When his prophecy of Rulon's resurrection flopped, he initially took eight of his father's widows. Wall also witnessed him banish 21 men and reassign their wives. And she saw her own father banish her brothers at Jeffs' instruction.

That Jeffs' timetables for the end of the world passed without event did not dent his standing as prophet, and his volatile and capricious ways had predictable consequences.

"Fear was such a part of my life," says Wall. "I was afraid of not being obedient enough. I was afraid of not being prayerful enough. I was afraid of the end of the world and the day that destruction would come to the land, and I was afraid that I would not be worthy enough to be lifted into heaven.

"Fear reigns so much of their lives. It's not just fear of the outside; fear is a controlling factor in their lives and I think the leaders know that."

Jeffs was principal educator, consigning girls' education to housekeeping and obedience, and even modifying to his taste the community's pastel 19th-century pioneer-style dresses.

"I was terrified of the outside world," says Wall. "I was taught from a young age that I was one of God's chosen people, that I already was on this one and only path to heaven so everybody on the outside was not as worthy as I was, and as Warren came into power he would tell us that the people on the outside were marked in heaven, and they were evil and other races were the servants of the devil.

"All races were marked by something their forefathers had done. Especially blacks. He had a thing for black people. He was very racist. I remember looking at the outside world and being afraid of it, but also almost pitying everyone out here."

While describing herself as religiously traumatised, Wall retains a belief in God and friendships with mainstream Mormons. The excesses she experienced, she says, were essentially the work of Jeffs.

Not so, according to some who were raised in earlier Fundamentalist Church of Latter Day Saints communities. They tell their stories of, say, 1950s childhoods of widespread sexual, physical and emotional abuse. Abuse, it seems, is entrenched.

Says Wall: "I am sure that most of it was not talked about, but we knew of daughters who had been abused by their fathers, or brothers who had abused sisters and stepsisters and cousins. I remember seeing a specific man or woman and asking why they were looked down upon and I remember my mother saying because they had been hurt. It seems like someone who has been hurt like that was treated different."

Abuse extended from infancy to marriage. "Women are told just to pass it off because they are supposed to do their husband's will," says Wall, who recalls envy, jealousy and competition among her three mothers.

Yet she says polygamy can work for some, although not as portrayed on Big Love , a television series depicting the trials and tribulations of polygamous marriage.

"They really sexed it up, Big Love . Sex and the money and the drama of it. I always laugh when I see Big Love because I always think if it was really like that there would be a lot more people that lived it."

While not formally in witness protection, Wall and Barlow, 30, and their two children aged three and one, live carefully.

Warren Jeffs faces another trial, this time in Arizona for which Wall again will be a witness. And she will testify against Steed when he faces the allegation of raping her.

She has thought of abandoning Utah, and even fleeing the United States, but has chosen to stay and help other sect refugees.

When Texas authorities raided the Yearning for Zion ranch, they sought her help in dealing with the 416 children removed from families. And while the children have been returned by court order, Wall is confident abuse charges will be pursued. "I have a responsibility to help these women who, if they want a way out, they can turn somewhere," she says. "Maybe I'll be doing that for the rest of my life. I want to go to school. I want to be something. I want to change the world somehow."

Ian Munro is the Herald's New York correspondent. The flight from abuse Elissa Wall milestones P July 7, 1986 : Born Salt Lake City in a birthing centre run by the polygamous Fundamentalist Church of Latter Day Saints to the second of her father's three wives, who together bore him 24 children.

P August 2000 : Concludes her education, graduating from eighth grade at the sect's school which for girls emphasised home economics and obedience to husbands.

P April 23, 2001 : Under instruction from the sect leader, Warren Jeffs, the 14-year-old Wall marries her 19-year-old first cousin, Allen Steed, who is now charged with raping her.

P November 2004 : Flees from the sect's Colorado City community just inside Arizona's northern border with Utah. With her is the man who will become her husband, Lamont Barlow. Of her 13 siblings from her father's second wife, only five girls remain in the sect; all the boys have been expelled or have fled.

P September 2007 : Appears as the key witness in the trial of Jeffs, who is convicted as an accomplice to rape.

P May 13, 2008 : Publishes Stolen Innocence , her account of growing up in the sect, marrying as a teen and testifying against Jeffs.