Doctor Who's Philip Hinchcliffe admits he didn't consider "the repercussions" of the Morbius Doctors

The sequence saw images of the Doctor's previous incarnations – as played by Jon Pertwee, Patrick Troughton and William Hartnell – displayed on a screen, which then displayed eight other mystery faces.

The scene has been the cause of much debate ever since, with Doctor Who fandom divided as to whether these eight faces were intended to represent incarnations of the Doctor before Hartnell's "First" – though Philip Hinchcliffe, producer on the series at the time, said (via 1996 reference book Doctor Who: A History of the Universe), "It is true to say that I attempted to imply that William Hartnell was not the first Doctor."

Speaking to RadioTimes.com to promote The God of Phantoms – the latest in his Philip Hinchcliffe Presents... series from audio drama producers Big Finish – Hinchcliffe said that the introduction of these so-called Morbius Doctors "wasn't thought out at all".

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Hinchcliffe's plan had originally been to feature well-known actors as these pre-Hartnell Doctors for something of a throwaway gag – but these plans were disrupted, meaning that a number of production staff, including Hinchcliffe himself, had to pose for the shots.

"We suddenly get a got a call – I think it was one of the production days when we were in the studio, probably rehearsing," Hinchliffe explained. "I think it was George Gallaccio, who was my sort of associate producer, who said they'd got a problem. I don't know if Equity got onto it or whatever, but we couldn't afford to have all these actors [in the photographs], each one being paid.

"He said, 'We need as many people as possible down in the photographic studio – now.' And so anybody who was in that day working on the show, or could be grabbed during that lunch hour, was corralled and marched down to wardrobe. I think [Doctor Who writer] Bob Banks Stewart happened to be there talking about another script, so he was marched off...

"We all piled down there and they just put all these funny hats on us all and shoved us in front of a camera. So it was totally ad hoc, really. It wasn't thought out at all. In fact, I don't think [script editor] Bob Holmes or any of us really thought about the repercussions of all these previous incarnations of the Doctor. We hadn't thought about it."

The final episode features images (see above) of Robert Holmes (who was also The Brain of Morbius's co-writer), production unit manager Gallaccio, production assistant Graeme Harper, director Douglas Camfield, production assistant Christopher Baker, director Christopher Barry, Robert Banks Stewart and Hinchcliffe.

Though the production team of the time didn't expect this moment to have far-reaching consequences, Doctor Who returned to the notion of versions of the Doctor before Hartnell's "First" in its most recent series, with Jo Martin's "Fugitive Doctor" being revealed as another such incarnation.

Series 12's finale The Timeless Children even featured a brief glimpse of the Morbius Doctors – back on BBC One after 44 years – during a sequence in which the Doctor (Jodie Whittaker) broadcasts her memories to escape the Matrix.

Read more: Philip Hinchcliffe: 'I was pushing the envelope on Doctor Who, but not irresponsibly'

Doctor Who: Philip Hinchcliffe Presents Volume 04: The God of Phantoms is available now from bigfinish.com.

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