The controversial Word of Faith Fellowship used its two church branches in Brazil to siphon young labourers on tourist and student visas to its 35-acre compound in rural Spindale, North Carolina, to work as 'slaves', an investigation by the Associated Press (AP) has found.

The 'slave pipeline' was used by the secretive evangelical church despite US law requiring that visitors on tourist visas are prohibited from performing work for which people would normally be compensated. Those on student visas are allowed some work, under circumstances that were not met at the Word of Faith Fellowship.

Some 16 Brazilian former members told the AP they were forced to work, often for no pay, and physically or verbally assaulted.

One of those was Andre Oliveira, who answered the call to leave his Word of Faith Fellowship congregation in Brazil to move to the mother church in North Carolina at the age of 18, when his passport and money were confiscated by church leaders, supposedly for safekeeping.

Oliveira said he was forced to work 15 hours a day, first cleaning warehouses for the church and later toiling at businesses owned by senior ministers. He said that any deviation from the rules risked the wrath of church leaders, ranging from beatings to shaming from the pulpit.

'They trafficked us up here. They knew what they were doing,' Oliveira said. 'They needed labour and we were cheap labour -- hell, free labour.'

He added: 'They kept us as slaves. We were expendable. We meant nothing to them. Nothing. How can you do that to people -- claim you love them and then beat them in the name of God?'

The Brazilians often spoke little English when they arrived. Many had their passports seized.

According to the AP investigation, many males worked in construction, while many females worked as babysitters and in the church's school.

One ex-congregant from Brazil told the AP that she was only 12 when she was first put to work.

The revelations of forced labour are the latest exposing years of abuse at the Word of Faith Fellowship.

Based on documents, recordings and interviews with 43 former members, AP reported in February that congregants were regularly punched, smacked and choked in an effort to 'purify' sinners.

A separate, previous report outlined how congregants were ordered by church leaders to lie to authorities investigating reports of abuse.

But the church has rarely been sanctioned since it was founded in 1979 by the sect leader Jane Whaley, a former maths teacher, and her husband Sam.

Under Jane Whaley's leadership, the Word of Faith Fellowship grew to around 750 congregants in North Carolina and a total of nearly 2,000 members in its churches in Brazil and Ghana and its affiliations in Sweden, Scotland and other countries.

Brazil is the biggest source of foreign labour and Whaley and her top lieutenants visit the Brazilian outposts several times per year, AP found.

Another former member, Thiago Silva, said that, then aged 18, he was excited when he boarded a plane in the Brazilian city of Belo Horizonte to fly to a Word of Faith youth seminar in North Carolina in 2001.

He soon learned, however, that there would be 'no happiness'. Silva, now 34, added: 'Brazilians came here for labour. I'm telling you, that's it...There's no free will. There's Jane's will.'

Former members alerted the authorities on at least one occasion, according to the investigation. In 2014, three ex-congregants told an assistant US attorney that the Brazilians were being forced to work for no pay, according to a recording obtained by AP.

'And do they beat up the Brazilians?' asked Jill Rose, now the US attorney in Charlotte.

'Most definitely,' one of the former congregants responded. Another said that ministers 'mostly bring them up here for free work'.

The former members said that Rose she never responded when they repeatedly tried to contact her in the months after the meeting.

Rose declined to comment, as did representatives of the Word of Faith Fellowship.