Dozens of people who were referred to the City Hearts Charity have been speaking out over homophobic attitudes of some senior staff, controlling behaviour from management and receiving counselling from people without training.
The charity - which pledges to support people of all race, gender and sexuality - is run by the Hope City Church and receives government-funding via the Salvation Army as part of the UK’s human trafficking contract to help victims, which it was awarded in 2011.
But two former residents plus ex-staff members came for ward to tell a Channel 4 news investigation of a litany of issues within the organisation, which is based in a building just off the Sheffield Parkway near Park Hill.
One of those interviewed, who was given the fake name of Ameila to protect her identity, was trafficked to the UK from Eastern Europe but having escaped ended up in one of the charity’s safe houses.
She claimed that as a gay woman she was subjected to homophobia by some senior staff.
Amelia said: "One of the staff said like you have the devil in you and you have to change that. They would ban any physical contact for me with people in the congregation, well women.
"I found it quite humiliating as I’m not doing anything, I’m not spreading disease. I’m not going to infect them. I’m not going to make them be gay.”
She added she felt like she was in “some sort of weird cult.”
Another woman called Holly, who had been abused before being rescued by police and taken to the charity in 2011, told how she felt "completely controlled” while in the care of the charity.
She added: "Although I’ve been abused by abusers in my past, this touches a different spot and is more painful.
"Within the refuge you’ve got no control they completely control you from your finances to what you eat to your decisions and your communication with the outside world.
"If you did watch TV it’s monitored but any mail coming in they would open your mail and if they didn’t want you to receive it then it would be discarded."
Several former employees also talked about being untrained for their roles.
Kat, a former lead pastor of Hope City Church and project manager of the charity, explained how aged 20 she was put in charge of a safe house caring for vulnerable people with no training or guidance other than prayer and worship.
She said: “As a shift leader, the person in charge of the whole shift, I remember I once walked into a room and one of the clients had self-harmed so horrifically. You’re walking into a situation where someone’s lying on the floor and you don’t know if they’re alive or not.
“There is blood everywhere and you also have a group of ten other women you’re also trying to look after, with one other volunteer.”
She added: "I had to do one to one sessions with them give them advice give them pointers put plans together for them for their progression but with absolutely no training with absolutely no professional kind of guidance in that sense.
"It was just always thrown on and put in a way of like we'll pray use god or use a bible scripture or something like that."
David Gilpin, senior pastor at Hope City Church, declined to be interviewed but said he's sorry to hear about the allegations and that the charity is investigating.
In a statement the charity said: "We seek to uphold the highest standards of excellence and diversity, and have been very disappointed to hear the allegations."
The charity pledged to investigate the claims and to "review our policies and procedures."
A Charity Commission spokesperson described the allegations as "deeply distressing" which "may point to failings" on the part of the charity trustees.
They added: "We are assessing Channel 4’s findings as a matter of urgency and require the trustees to respond to our questions. We will also be engaging with the charity’s funder, the Salvation Army, to ensure it is carrying out appropriate due diligence checks on the partners it works with.”
The Home Office has also pledged to work with the Salvation Army to "urgently look into what happened at City Hearts."
A Salvation Army spokesperson said: "The support provided to the individuals identified to us by Channel 4 was given outside the specialist support subcontracted to City Hearts by the Salvation Army.
"However, in light of these allegations we are looking into this situation including bringing forward a regular safeguarding inspection of City Hearts.”