The RTÉ Investigations Unit has uncovered a number of unregulated recovery homes for addicts.
In a report, aired on RTÉ One tonight, one church, Victory Outreach, was found to be running such homes with poorly trained staff.
Victory Outreach is part of an international Evangelical Christian church and has a number of churches and recovery homes in Ireland.
There is no waiting list and anyone who calls for help will receive a bed from the organisation.
The investigation focused on the Maynooth branch, which did not provide any professional counselling or structured counselling sessions for residents.
Residents were not given chemical assistance to help with their withdrawals, despite the medical dangers of this approach.
They were instead told to use prayer.
Furthermore, residents were told to hand over €150 of their welfare payments.
Many were sent out fundraising for the church, which is a registered charity.
One resident spoke of how he was arrested for fundraising without a permit.
He said the church refused to write a letter to explain why he was selling tickets for the charity.