Dozens of ex-Synagogue Church of all Nations members - five British - allege atrocities, including rape and forced abortions, by Nigeria's late TB Joshua.
The allegations of abuse in a secretive Lagos compound span almost 20 years.
The Synagogue Church of All Nations did not respond to the allegations but said previous claims have been unfounded.
TB Joshua, who died in 2021, was a charismatic and hugely successful preacher and televangelist who had an immense global following.
The BBC's findings over a two-year investigation include:
- Dozens of eyewitness accounts of physical violence or torture carried out by Joshua, including instances of child abuse and people being whipped and chained
- Numerous women who say they were sexually assaulted by Joshua, with a number claiming they were repeatedly raped for years inside the compound
- Multiple allegations of forced abortions inside the church following the alleged rapes by Joshua, including one woman who says she had five terminations
- Multiple first-hand accounts detailing how Joshua faked his "miracle healings", which were broadcast to millions of people around the world
One of the victims, a British woman, called Rae, was 21 years old when she abandoned her degree at Brighton University in 2002 and was recruited into the church. She spent the next 12 years as one of Joshua's so-called "disciples" inside his maze-like concrete compound in Lagos.
"We all thought we were in heaven, but we were in hell, and in hell terrible things happen," she told the BBC.
Rae says she was sexually assaulted by Joshua and subjected to a form of solitary confinement for two years. The abuse was so severe, she says she attempted suicide multiple times inside the compound.
The Synagogue Church of All Nations [Scoan] has a global following, operating a Christian TV channel called Emmanuel TV and social media networks with millions of viewers.
Throughout the 1990s and early 2000s, tens of thousands of pilgrims from Europe, the Americas, South East Asia and Africa travelled to the church in Nigeria to witness Joshua performing "healing miracles".
At least 150 visitors lived with him as disciples inside his compound in Lagos, sometimes for decades.
More than 25 former "disciples" spoke to the BBC - from the UK, Nigeria, US, South Africa, Ghana, Namibia and Germany - giving powerful corroborating testimony about their experiences within the church, with the most recent experiences in 2019.
Many victims were in their teens when they first joined.
In some of the British cases, their transport to Lagos was paid for by Joshua, in co-ordination with other UK churches.
Rae and multiple other interviewees compared their experiences to being in a cult.
Jessica Kaimu, from Namibia, says her ordeal lasted more than five years. She says she was 17 when Joshua first raped her, and that subsequent instances of rape by TB Joshua led to her having five forced abortions while there.
"These were backdoor type… medical treatments that we were going through… it could have killed us," she told the BBC.
Other interviewees say they were stripped and beaten with electrical cables and horse whips, and routinely denied sleep.
On his death in June 2021, TB Joshua was hailed as one of the most influential pastors in African history. Rising from poverty, he built an evangelical empire that counted dozens of political leaders, celebrities and international footballers among his associates.
He did, however, attract some controversy during his lifetime when a guesthouse for church pilgrims collapsed in 2014, killing at least 116 people.
The BBC's investigation, which was carried out with international media platform openDemocracy, is the first time multiple former church insiders have come forward to speak on the record. They say they've spent years trying to raise the alarm, but have effectively been silenced.
A number of our witnesses in Nigeria claim they were physically attacked, and in one case shot at, after previously speaking out against the abuse and posting videos containing allegations on YouTube.
A BBC crew that attempted to record footage of the church's Lagos compound from a public street in March 2022 was also fired at by the church's security, and was detained for a number of hours.
The BBC contacted Scoan with the allegations in our investigation. It did not respond to them, but denied previous claims against TB Joshua.
"Making unfounded allegations against Prophet TB Joshua is not a new occurrence… None of the allegations was ever substantiated," it wrote.
Four of the British citizens who spoke to the BBC say they reported the abuse to the UK authorities after escaping the church. They say no further action was taken.
In addition, a British man and his wife emailed eyewitness accounts of their ordeal and video evidence - including recordings of being held at gunpoint by men describing themselves as police who are also members of Scoan - to the British High Commission in Nigeria in March 2010 after fleeing the church.
In his email, the man said his wife had been repeatedly sexually assaulted and raped by Joshua. He warned the commission that other British nationals were still inside the compound facing atrocities.
He also says no action was taken.
The UK Foreign Office did not respond to these claims, but told the BBC that it takes all reports of crime, including sexual assault and violence against British nationals overseas, very seriously.
Scoan continues to thrive today, under the leadership of Joshua's widow, Evelyn. In July 2023, she led a tour of Spain.
Anneka, who left Derby in the UK to join Scoan at the age of 17, told the BBC she believes there are many other victims who have yet to speak out. She hopes further steps will be taken to uncover Joshua's actions.
"I believe the Synagogue Church of All Nations needs a thorough investigation into why this man was able to function for so long the way he did," she said.