Now about to celebrate its 60th anniversary, Star Trek: The Original Series has become one of the most iconic sci-fi series of all time – but there was quite the kerfuffle when it came to airing in Britain.

While Gene Roddenberry's beloved sci-fi began in the US in 1966, it took three years to arrive across the pond and, while it was produced in colour in the States, many British households only owned a black-and-white TV set.

The first episode of Star Trek to air in Britain was also not the very first episode of the show. Although the pilot, The Man Trap, was the first episode to air in the US, the BBC chose the more action-packed episode Where No Man Has Gone Before (now known as the second pilot), capitalising on the lead-up to the Apollo 11 launch on 20 July 1969.

But, most dramatically for British audiences, four episodes of Star Trek: The Original Series – plus one episode of The Next Generation – were banned from TV for years.

At the time, the BBC said: "There are no plans to screen the four episodes because we feel that they deal most unpleasantly with the already unpleasant subjects of madness, torture, sadism and disease.

"You will appreciate that account must be taken that out of Star Trek's large and enthusiastic following, many are juveniles who would watch the programme no matter what time of day the series is put into the programme schedules."

It's reported that Roddenberry addressed the ban in 1984 at a news conference in Newcastle, saying: "I disagree [with the ban] very much. Empath to me was a beautiful story... If someone is to say to me, 'You can't have hurt and pain', I say, 'Nonsense!'

"Suffering and pain are a part of life. They should be handled, and handled well. I feel the same way about violence and sex."

So, what exactly were the offending episodes?

1. Miri (TOS season 1 episode 8)

First aired in the US: 27 October 1966

First aired in Britain: 2 December 1970

Written by Adrian Spies and directed by Vincent McEveety, Miri sees the crew of the USS Enterprise discover an identical version of Earth which has been ravaged by a mysterious plague. The only survivors appear to be children – although a later twist reveals that the survivors are actually over 300 years old, only ageing one month every century.

Miri was first broadcast in December 1970, with the BBC receiving a number of complaints, which led to the episode being left out of a repeat run of the series in the 1980s. Of course, some fans complained about the omission – and were met with the standard BBC response detailed above.

Thankfully for those who complained, the ban was lifted by the time the series was repeated in the 1990s.

2. Plato's Stepchildren (TOS season 3 episode 10)

First aired in the US: 22 November 1968

First aired in Britain: 22 December 1993

Plato's Children also left the BBC unimpressed, after depicting the crew of the Enterprise meeting a telekinetic – and rather sadistic – race of humanoids. The episode was not shown until the 1990s due to depictions of "sadism" and "torture".

After answering a distress call, the crew encounter the arrogant so-called "Platonians", and are forced to perform for their entertainment. Alexander, the one Platonian who doesn't possess telekinetic powers, ends up returning to the Enterprise with Kirk and his crew.

Separately, the episode is also famous for depicting one of the earliest instances of an interracial kiss on US TV (between William Shatner's Captain Kirk and Nichelle Nichols's Nyota Uhura). Speaking specifically about the kiss, Nichols recalled the episode receiving a huge response from fans, "all of it very positive".

3. The Empath (TOS season 3 episode 12)

First aired in the US: 6 December 1968

First aired in Britain: 5 January 1994

Written by Joyce Muskat and directed by John Erman, The Empath saw the crew of the Enterprise subjected to torturous experiments by a group of powerful Vians. Again, it wasn't aired by the BBC until 1994 due to disturbing content.

The crew arrive on the planet Minara II, which is about to go supernova, and meet a mute women who McCoy names Gem, who turns out to be an empath, managing to heal the crew at various points. The Vians perform torturous experiments on the crew and test Gem in various ways, figuring out which race they should save from the incoming supernova.

Eventually, Kirk proves that the Vians should save Gem's people, with the crew being able to safely return to the Enterprise.

4. Whom Gods Destroy (TOS season 3 episode 14)

First aired in the US: 3 January 1969

First aired in Britain: 19 January 1994

Whom Gods Destroy was initially banned from British TV due to the "sadistic" plot elements and because of a risqué dance performed by the character Marta, which was deemed unsuitable for children. The episode was also not shown on German TV until 1988.

The episode, which took 25 years to arrive on the BBC, sees the Enterprise arrive on the planet Elba II at a facility that houses the criminally insane – only to find it's been taken over by the inmates. Kirk and Spock are imprisoned, with a shapeshifting inmate attempting – and failing – to impersonate Kirk. Another inmate, Marta, attempts to seduce and kill Kirk.

5. The High Ground (TNG season 3 episode 12)

First aired in the US: 29 January 1990

First aired in Britain in full: May 2006 (on Sky One) and September 2007 (on the BBC)

While The Original Series bore most of the brunt of the BBC's bans, The Next Generation didn't get away scot(ty)-free.

Written by Melinda M Snodgrass, the episode sees Data (Brent Spiner) use the "Irish unification of 2024" as an example of violence successfully achieving a political aim. At the time, both the BBC and Irish broadcaster RTE refrained from showing the episode - although a 2024 BBC News article notes that there's some "murkiness" about how this decision was reached.

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