One of five people charged with beating a fellow church member to expel 'homosexual demons' has admitted in court that she started the assault by slapping the man.

Sarah Anderson testified yesterday that she told other leaders at the evangelical Word of Faith Fellowship in Spindale, North Carolina, that she thought that Matthew Fenner was unclean and sinful.

A minister, Brooke Covington, is standing trial on kidnapping and assault charges.

Anderson says Covington began the confrontation by screaming at Fenner after a January 2013 service at the church.

She says that she then slapped Fenner, before Covington and about 30 others joined in, slapping, beating, choking and screaming at the man for two hours.

Previously when Fenner testified, he said that he thought he was 'going to die' when members of the church beat and choked him for two hours to expel his 'homosexual demons'.

Fenner, 23, said Covington pointed out his sexual orientation, saying, 'God said there is something wrong in your life'.

Fenner said that he had cancer as a child and had just had a biopsy one week before he was assaulted. 'I'm frail and in my mind, I'm thinking, "Is my neck going to break, am I going to die?''' Fenner said.

Prosecuting, Garland Byers said during opening statements that Covington 'directed and participated in' the assault.

The Associated Press (AP), having interviewed 43 former members of the 750-member evangelical church, reviewed documents and covertly made recordings, reports that sinners are routinely 'purified' by being punched, choked, and thrown to the floor as a means of expelling demons. One witness told the AP that Fenner's beating 'made me sick'.

The church was founded in 1979 by a former maths teacher, Jane Whaley, and her husband Sam, a former used car salesman. It has grown from just a few followers to thousands in its North Carolina congregation and at churches in Brazil, Ghana, and other countries.

The AP reported that the church has scores of strict rules to control congregants' lives, including whether they can marry or have children, and that failure to comply often triggers a humiliating rebuke from the pulpit or, worse, physical punishment.

Members reportedly cannot watch television, go to the movies, read newspapers or eat in restaurants that play music or serve alcohol.