Controversial right-wing Christian leader and pro-gun lobbyist, the Rev Peter Hammond, has been arrested and charged with treason and insurrection in Sudan, according to his Frontline Fellowship organisation.

The organisation said Hammond was arrested together with a Sudanese bishop by intelligence agents of the rebel Sudanese People's Liberation Army (SPLA) in a church building in Yei province on Saturday.

Frontline Fellowship official Charl van Wyk said from Cape Town on Wednesday that Hammond and the Episcopal Church of Sudan's Bishop Bullen Dolli were arrested while lecturing at the Biblical Worldview Seminar.

Hammond's passport was confiscated.

The two were then taken away for a three-hour interrogation by SPLA personnel.

Van Wyk said Hammond had left South Africa with fellow Christian worker Timothy Kellar, who escaped arrest when soldiers held someone else they mistook for Kellar. Kellar left for Nairobi, Kenya, soon afterwards.

"At present Peter and the bishop are under house arrest and being detained against their will. The SPLA would not let them leave on two flights that were organised," Van Wyk said.

The SPLA is a rebel group fighting against the Sudanese government's Islamic rule.

The rebels effectively control almost the entire southern part of the country.

The brush with the Sudanese authorities isn't the first for Hammond - the ruling Muslim government declared him an undesirable figure in 1999, amid accusations of gun-running.

The government accused Hammond of supplying military hardware and training to the SPLA.

Hammond is the founder and director of the Frontline Fellowship, a Cape Town-based right-wing Christian organisation that is devoted to spreading the gospel in conflict situations.

Earlier this year, a book he co-authored drew calls for a banning, with gay and lesbian groupings regarding it as homophobic and as spreading hate speech against them.

However, the Film and Publications Board only imposed age restrictions on the book, entitled The Pink Agenda: The Ruin of the Family.

The foreign affairs department could not confirm Hammond's arrest on Wednesday night. - Sapa