How we made: BBC mockumentary Ghostwatch

The script focused on the story of two girls, Kim and Suzanne Early (Cherise and Michelle Wesson), and their mother Pam (Brid Brennan), who lived in a reportedly haunted council house in Northolt, London. It was presented as a “live ghost hunt”, with reporters, interviewers and a film crew in the house, and an anchorman in the studio. To quote the screenplay: “Certain parts will be played by real television personalities, using their true names.”

I had never read anything as fresh and immediately started researching how to make the story, which was written by Stephen Volk, feel as real as possible. All of the adult cast – Michael Parkinson, Sarah Greene, Mike Smith, Craig Charles, each playing themselves – understood the concept, and were wholeheartedly behind the piece. Raymond “Pipes” Tunstall, the ghost haunting the Early family, was played by Keith Ferrari, a very game supporting artist in a non-speaking part. While he supplied the poltergeist’s physical presence, I ended up providing his guttural voice. We had done a one-hour recording session with a voiceover artist but that hadn’t cracked it.

I was trying to feature the Pipes character as much as possible: I seem to remember 13 being a satisfying number of appearances. But, as you can imagine, when it came to the cutting room, counting these wasn’t the focus of our work, and a couple were cut back. I was reaching for hyperrealism in performance, though I’m not saying I always achieved it.

It was a leap of faith on my part that Ghostwatch would air on Halloween. We hoped it would, but the production had been commissioned as a Screen One BBC drama film. I wasn’t seen as a documentary or studio director and I certainly didn’t have any control over scheduling, but it happened that there was a Screen One slot available on Halloween. A happy accident, perhaps.

Many viewers thought the programme was a real-time documentary, including, apparently, Michael Parkinson’s mother. Hopefully she deduced it was staged before his climactic possession scene. The BBC received 30,000 complaints, and imposed a 10-year ban on it being shown again. I believe our producer received a letter from one woman asking for compensation so she could buy a new pair of trousers for her husband, as he had soiled the ones he was wearing.

I definitely didn’t set out to cause mass hysteria. But I wasn’t trying to make it look like a conventional BBC movie, either. I thought the fact that it was a drama was obvious: it was trailed as such by the continuity announcer, and it opened with a “written by” credit.

Ghostwatch was using tried-and-tested formats to make us question the “truth” of television. On the front page of the script, Stephen wrote a quote from John Waite about his cousin Terry Waite, the former hostage and a humanitarian, when he heard of his release. “I won’t believe it until I see it on TV.”

I can’t remember whether I was allowed to read the script before auditioning: it seemed to be rather hush-hush. But I was excited to be trying out for a female director, female casting director and female producer. A rare thing in 1992.

I was blown away by Stephen’s writing and vision. He took me to hear lectures on the paranormal and gave me background reading. As far as I was concerned, I was making a very contemporary drama. It was a Screen One production with a cast list appearing in the Radio Times, so we were unprepared for the reaction Ghostwatch received from people who didn’t realise it was fictional.

Michael Parkinson, playing the host presenter, was a true pro. He was very respectful to everyone. He’s a fan of Gershwin and the great American songbook, and I remember us quoting lyrics to each other between takes. I didn’t experience any on-set spookiness. Not even when my character is listening to a recording of the poltergeist’s voice.

Ghostwatch got 11 million viewers and came in under budget, but talk of a Bafta nomination was quietly crushed, and I feel sad that the controversy meant that Lesley and producer Ruth Baumgarten’s talents weren’t recognised. Over the years, however, it has garnered cult status. Jonathan Ross, Derren Brown, Mark Gatiss and Andy Nyman are fans, and a couple of years ago I did a Q&A where people came dressed as Lin Pascoe, complete with wig and designer suit. Some of them weren’t even born when Ghostwatch aired in 1992.

Looking back now, it seems amazingly ahead of its time: pre-Big Brother, and seven years before The Blair Witch Project. Apart from being a brilliant ghost story, what it was really saying was: “Be very careful what you watch, question everything, and do not allow yourself to be manipulated.”

On Halloween, we all gathered to watch it on BBC One. I got home later to an answerphone message from a comically enraged Judi Dench, complaining that I’d ruined her night. She had sat down to watch Ghostwatch but – having directed me in the theatre that summer – knew as soon as she saw me on screen that it wasn’t real.

Ghostwatch is available on DVD. A National Séance Live Twitter viewing begins on 31 October.