He’s pushed around the floor, spinning in circles.

Two pastors pray heavily over him, shouting and speaking in tongues. "Let there be a release!" they cry. "Let the fire come upon him!"

For over twenty minutes they lay hands on him.

They’re calling on the Holy Spirit to enter him - and push something else out.

It’s barely been an hour since our reporter first told Pastor Gbenga Samuel that he’s gay.

The pastor claimed that several parts of our reporter had come 'under the control of Satan'. Credit: ITV News secret filming

He’s already been told he needs to embark on a "complete mind reorientation", including a week of intense Bible studies.

Winners' Chapel openly claims that its mission is "liberating men everywhere from every oppression of the devil", and at its branch in Dartford, that includes homosexuality.

Our undercover reporter spent two months attending the church - one of the largest in Britain - where several pastors made clear they could help stop him being gay.

He has met four in total, with a hidden camera capturing his pre-arranged appointment with Pastor Gbenga Samuel.

Over the course of their meeting, Pastor Gbenga told our reporter "something shifted" in the process of his life, "which God can fix".

The pastor is calling on the Holy Spirit to 'push something else out' of our undercover reporter. Credit: ITV News secret filming

The pastor drew a diagram of the spirit, body and soul, and claimed that several parts of our reporter had come "under the control of Satan".

He reassured our reporter that he was young, with a strong will, which is "one advantage that you have over the devil".

But he warned him that society would try to convince him that being gay was "the right thing".

Most shockingly, he claimed that messages of acceptance we see and hear in modern society about gay people have been "carefully scripted" by Satan, drawing a comparison with the way Germans were brainwashed by Nazi propaganda.

"During World War II, how was Hitler able to get boys to gas millions of Jews in the gas chamber?" he asked our reporter.

It is not unusual for a pastor to try to fill a person with the Holy Spirit. Credit: ITV News secret filming

He continued: "These boys were specially trained in special school where it was played over to them, over and over, during the day and during the night, the propaganda that the Jews are the bad people, and they should be exterminated."

A particularly toxic analogy, given that the Nazis also gassed thousands of gay people.

Done with his theory, Pastor Gbenga was ready to put some of it into practice. Our reporter followed him to an empty church hall, which was about to be filled with intense prayer.

What followed was a practice common in many churches - it is not unusual for a pastor to try to fill a person with the Holy Spirit.

Indeed, for many Pentecostal Christians it is a happy experience. But for our reporter, the aim wasn’t just to bring him closer to God, but to distance him from homosexuality.

Several pastors at the Winners' Chapel made clear they could help stop him being gay. Credit: ITV News secret filming

Loud, physical and exhausting, what our cameras captured hasn’t been broadcast before in Britain, but it isn’t hard to find.

We’ve spent six months investigating several organisations to try and understand the true extent of so-called gay conversion therapy.

Indeed, the government estimates that tens of thousands of LGBT people have either been offered conversion therapy or been through it. And as our series of reports will detail, the nature of it varies widely.

Most of the victims are too afraid to speak out, due to the kickback within their own communities.

But one woman - whose name we’re keeping anonymous - was brave enough to tell us how her family called a pastor to her home, in order to exorcise her of her homosexuality.

"His words were along the lines of ‘there’s something inside of you that needs to come out’.

So whether that is a demon or a bad spirit, it’s something that’s in me", she told us. "And it’s almost like he had his hand on my chest to draw something out, speaking in tongues. All the family were gathered around me, praying, laying hands on me."

Winners' Chapel church in Dartford. Credit: ITV News

The prayer lasted for three hours, leaving her feeling like "damaged goods, defective goods".

It took her years to get over the shame and stigma of her experience and finally accept her sexuality.

In that case, the pastor wasn’t from Winners' Chapel, which is just one of a rapidly growing number of Pentecostal churches in Britain.

Pastor Paul Bailey, who condemns conversion therapy, estimates that it is common in a high proportion of Pentecostal churches.

As ITV News exclusively reported in July, the government wants to ban it, but the challenge is policing something which is so intrinsically linked to religious freedoms.

For Pastor Paul, the answer is simple. "Rights come with responsibilities," he told us. "There are many things we no longer do because we know better.

"There is clear scripture that says you should beat your children.

"We ignore that because we recognise that beating children is harmful. This is a harmful practice. Your freedom does not mean you have the freedom to negate and oppress someone who’s different."

The Evangelical Alliance, which represents thousands of Pentecostal churches in Britain, said "churches and their leaders must be held accountable when they misuse their influence over others. Winners' Chapel International is not a member of the Evangelical Alliance and we would have serious concerns regarding the behaviour depicted."

In response to our filming, Winners' Chapel said they would conduct an internal investigation into our allegations. But they deny that they engage in any form of conversion therapy.

They say they are open to all people and take "inclusion and diversity very seriously". They say they comply with the law and follow the "biblical teachings of love for everyone regardless of their belief, gender, background or sexual orientation".

The question now is whether any kind of ban introduced by the Government will cover these practices.

Salvation - of its own kind - could be coming for LGBT people subjected to the harm of conversion therapy.

Our undercover reporter writes:

From the first moment I mentioned my sexuality, presenting as a gay man to pastors at Winners’ in Dartford, their attitude was immediate and obvious.

They told me that I didn't need to feel guilty about what I said I was, but that wasn't in any way reassuring.

To them, it was clear that being gay was both a sin, and in some sense a sickness that is both mental and spiritual.

They described it as demonically-influenced, and so my lack of guilt was because I didn't necessarily cause it.

I went through hours of counselling and prayer sessions, all directed at ridding me of my homosexuality.

Sometimes the prayers in themselves seemed harmless, such as for God to direct me and guide me.

I felt it changed from something that could have been comforting to something sinister and potentially traumatising.

Prayer is, for many people, a powerful and spiritual experience.

Belief in God helps many religious people in their lives in numerous ways. I grew up in the church and understand how faith can be a strength and a comfort.

But my experience at Winners' showed that there is a disturbing ignorance around issues of sexual orientation in some churches.

Some of the pastors who counselled me made highly disturbing comments, comparing me to brainwashed children in Nazi Germany.

There was little sensitivity about how this could have been incredibly damaging to me.