Children who were sexually abused by Jehovah's Witnesses were allegedly told by the organisation not to report it.
Victims from across the UK told the BBC they were routinely abused and that the religion's own rules protected perpetrators.
One child abuse lawyer believes there could be thousands of victims across the country who have not come forward.
The organisation said it did not "shield" abusers and any suggestion of a cover-up was "absolutely false".
'Bring reproach on Jehovah'
BBC Hereford and Worcester spoke to victims - men and women - from Birmingham, Cheltenham, Leicester, Worcestershire and Glasgow, one of whom waived her right to anonymity.
Louise Palmer, who now lives in Evesham, Worcestershire, was born into the organisation along with her brother Richard Davenport, who started raping her when she was four. He is serving a 10-year prison sentence for the abuse.
The 41-year-old, formerly of Halesowen, West Midlands, said she was told not to go to police.
Former Jehovah's Witnesses have been speaking to the BBC about abuse:
"I asked [the organisation], 'what should I do? Do you report it to the police, [or] do I report it to the police'?
"And their words were that they strongly advised me not to go to the police because it would bring reproach on Jehovah."
Another woman, from Worcestershire, said she was sexually abused as a child by a friend of her brother.
She said she told her parents and elders in the congregation what happened and they advised her not to report it.
"It started off just being very cuddly and I was always a very tactile little girl, but it gradually got worse and worse.
"It escalated until... he started raping me."
Jehovah's Witnesses movement at a glance:
Jehovah's Witnesses are members of a movement best known for their door-to-door evangelistic work.
Child abuse lawyer Kathleen Hallisey said there were concerns that the organisation's procedures compromised child safety.
"[For example] in order for [victims] to take allegations of sexual abuse further, they have to have two witnesses to the abuse," she said.
The 'two witness' rule - Felicity Kvesic, BBC News
I've spoken to multiple victims who have told me of the abuse they have suffered while in the Jehovah's Witnesses organisation.
What most of them keep coming back to is something known as the "two witness rule".
It is a procedure set by the main governing body of the religion and means for any sin committed, there must be two witnesses to it in order for the elders of the congregation to take any action.
The problem with this is it can be rare to have witnesses in cases of abuse.
The victims I've spoken to said the organisation self-polices and teaches members to avoid interaction with outside authorities or to take another member of the religion to court.
To do so, they say, could lead to expulsion from the religion.
In a statement the organisation said "any suggestion that Jehovah's Witnesses covered up child abuse was absolutely false".
It said victims and their parents had "the absolute right to report the matter to the governmental authorities" and reporting so was "not contingent on the number of witnesses to the offence".
It described child abuse as a "heinous crime and sin" and said the congregation did not "shield abusers from the authorities of the consequences of their actions".
The statement added "loving and protective parents" were the "best deterrent to child abuse" and elders provided "abuse victims and their families with spiritual comfort from the Bible".
In 2013 the Charity Commission started an inquiry into safeguarding issues in the Watch Tower Bible and Tract Society of Britain - the UK's main Jehovah's Witnesses organisation which the commission regulates.
Its inquiry continues.
For information and support for anyone affected by sexual abuse, including sources of support for children, young people and concerned parents, visit listings on BBC Action Line.
Photos - The Watchtower pamphlets - a free monthly publication of Jehovah's Witnesses.
