A Star Trek episode that made reference to an 'Irish unification in 2024' is still banned in Ireland.

Episode 12 of series three, titled The High Ground, was released in 1990, and involves a terrorist organisation taking a crew member of the Federation Starfleet starship USS Enterprise-D hostage in a bid to further their aims.

But a controversial moment in which an android character named Data, played by Brent Spiner, cites the 'Irish unification in 2024' as an example of a political aim achieved through violence, meant the episode only been shown once in Ireland in the 34 years since its release.

So great was the concern over the line's possible ramifications that the episode, which was first broadcast in the US, was neither shown on the BBC or Ireland's RTV network.

A redacted version was aired on Sky without the sensitive line in 1992. 

The High Ground was finally broadcast on the BBC on September 29 2007, in what is thought to be its only transmission.

Apart from Irish unification, Data gives two other examples of violence successfully achieving a political cause: Mexico's independence from Spain, and the Kenzie rebellion (an event in the Star Trek universe). 

The decision not to air the episode in 1990 reflects the febrile political situation at the time, during the Troubles in Northern Ireland, amid terrorist threats from the Provisional IRA, which had stated aims to liberate the region from British rule.