Star Trek trans character, Gray, will be played by trans actor Ian Alexander

 Star Trek trans character, Gray, will be played by trans actor Ian Alexander.

Sci-fi franchise Star Trek is set to introduce its first transgender and non-binary characters.

The characters are to appear in the third series of Star Trek: Discovery, producers said on Wednesday.

The trans character, Gray, will be played by trans actor Ian Alexander, and likewise non-binary Adira will be portrayed by Blu del Barrio.

"Star Trek has always made a mission of giving visibility to underrepresented communities," said a producer.

The show's co-runner and executive producer Michelle Paradise added: "It believes in showing people that a future without division on the basis of race, gender, gender identity or sexual orientation is entirely within our reach."

The programme, which will begin again next month on US TV network CBS, previously featured the first married gay characters in the franchise's history; while Sonequa Martin-Green also became the first Black woman to lead a Star Trek TV series.

In an interview with GLAAD del Barrio said: "When I got the call that I'd been cast as Adira, I hadn't yet told the majority of my friends and family that I was non-binary.

"So when this happened, it felt like the universe saying 'go ahead'."

Anthony Rapp, one of the show's stars, tweeted: "I cannot wait for you all to meet these beautiful souls and wonderful artists. I am so so so proud of them and happy that they are a part of our show".