The FBI has launched a probe into a secretive Christian church that was the focus of a recent BBC investigation.
The church has no official name but is often referred to as The Truth or the Two by Twos.
The sect has recently been rocked by a sexual abuse scandal, with the names of hundreds of alleged perpetrators given to a hotline set up for survivors.
An ex-minister who abused a boy in the 1980s told the BBC he had "no reason" to be concerned about the FBI probe.
BBC confronts man who abused boy in secretive Christian church
Last month's BBC investigation looked into claims of child sexual abuse spanning decades within the church.
One ex-minister, Robert Corfield, admitted when confronted that he sexually abused a boy, Michael Havet, in Canada in the 1980s.
Mr Corfield said he wasn't aware of an FBI investigation.
"I'm just leaving it all in God's hands and willing to accept whatever he allows to happen, so I'm not concerned about it," he said on Wednesday.
His name is one of more than 700 given by people to a hotline set up by a group called Advocates for The Truth (AFTT) to report sexual abuse within the church.
In a statement, the FBI said that it was "seeking the public's help in identifying victims of abuse that has occurred within a religious group".
It said the abuse "dates back to the 1980s".
The agency said that the group "traditionally does not have a name" but is widely referred to as 2x2, The Way, The Truth, and The Church With No Name.
The investigation has been welcomed by AFTT. The group was founded last year by Americans Cynthia Liles, Lauren Rohs and Sheri Autrey.
All the women used to belong to The Truth and Ms Rohs and Ms Autrey say they were abused by the same man.
"The FBI investigation brings validation and potential justice to survivors that have been silenced by their community for generations. A community that should have been wrapped around survivors with unconditional love, safety and communal care," AFTT said in a statement.
"For many, reporting abuse will be the first steps in their healing journey."
Ms Autrey, who stepped down from AFTT in December, told the BBC that she hopes for "full exposure and accountability and the opportunity for justice for survivors".
"I believe the response from the organisation itself will be the exact same as it always has been, where they say the right words but continue with no correct and tangible actions.
"An exact replication of what we've seen since it's been exposed in the last 11 months, and what has been tried to be exposed for the last 38 years in my case and for decades by countless other survivors."
Mr Havet, who was abused by Mr Corfield for six years in the 1980s, said "the rug has been burned where they have been hiding everything underneath".
He added that the care and support he is receiving now is "so much different" to when he first spoke out in the 1990s.
"It's 2024, the FBI is knocking on doors," he said.
The church's leadership has not responded to the BBC's request for comment.
The group is believed to have up to 100,000 members worldwide, with the majority in North America. It has a notable following in the UK, Ireland and Australia.
It was founded in Ireland by William Irvine, a Scottish evangelist, in 1897 and is built around ministers spreading New Testament teachings through word-of-mouth.
One of its hallmarks is that ministers give up their possessions and must be taken in by church members as they travel around, spreading the gospel. This makes children living in the homes they visit vulnerable to abuse, insiders say.