We set out to ask if Scientology was changing. It's an organisation with a chequered history, and a very colourful founder. It's been described as corrupt and sinister in courts in the UK. But the Church says that's all in the past, and it's just opened a new HQ in London.
As part of his investigations, our reporter John Sweeney (more from him here) had been shown an exhibition entitled the 'Industry of Death'. Scientologists believe that all psychiatry should be eradicated, and that it is evil in every form. Like everything to do with Scientology, their views are absolute.
In that exhibition John had seen representations of needles being pushed into children's eyes, he'd seen torture imagery, all of which Scientologists say is legitimate. He'd been talking to Scientologists and ex-Scientologists all week, they'd been dogging his every step, following him, and interrupting interviews that he'd been doing. At one point he was conducting an interview when a spokesman for the Scientologists turned up unannounced in the middle of a car park, to challenge John for "interviewing a pervert".
The whole thing came to a head when the spokesman accused John of going too soft on that interviewee, and John completely lost it in a way that I don't condone. We're not broadcasting the clip to promote the programme because we're proud of it - we're showing it because it's been on You Tube and the BBC is being criticised for it - and we don't want to hide it. We would have included it in the film in any case. I'm very disappointed with John, and he's very disappointed.
But when you watch the programme (which you will be able to do on our website after tonight's transmission), and you see what goes before and what comes after, you see a portrait of an extraordinary organisation which will not accept any criticism of itself whatsoever. It's not a question of us setting out to call Scientology a cult - it's just a question of us asking legitimate questions, and their organisation being unwilling to engage seriously with us. And when you go in as a journalist to try and deal with that, it's explosive. I'm now dealing with a situation in which the Church of Scientology has released a video to all MPs and peers accusing Panorama, of staging a demonstration outside one of their offices in London and making a death threat - or as they call it, a terrorist death threat - against Scientologists. The BBC, accused of terrorism.
The Church did, at first, agree to be involved. Over a day and a half, they organised formal interviews for us - they wanted us to talk to actresses Anne Archer and Kirstie Alley, as well as other celebrities and sports stars. They lined them all up, one after the other, and they talked about what Scientology meant to them. They were convincing and strong - Kirstie Alley in particular was very persuasive. John asked why some people say that it's a sinister cult, and about claims of brainwashing. Which, for the record, is not an allegation we've made - I don't want Scientologists in the UK to think that that's our view.
We completed the interviews, then three or four days before transmission, we received solicitors' letters from California saying that the interviewees no longer wanted to take part. So we were obliged to remove them.
In a sense, they've shot themselves in the foot by refusing to allow us to broadcast those viewpoints, when that was what we wanted to do. The Church rejects all criticism, and disputes that they offered us conditions on access which we couldn't accept.
The BBC's head of current affairs has reviewed our footage and, apart from the moment where John loses his temper, he's happy that none of it breaches the BBC's guidelines. The Scientologists claimed that we breached Ofcom's guidelines over 150 times - though I think that's for the regulator to assess, not the Church.