Shortland Street fans are threatening to abandon the beloved Kiwi series after a character was killed on Wednesday night's episode of the show.

On Tuesday's episode, Kylie Brown (Kerry-Lee Dewing) attempted to give Ali Karim (Tane Williams) a lethal dose of morphine but was interrupted just in time, leading fans to believe Ali would survive.

However the episode ended later that night when Ali's wife Dawn Robinson (Rebekah Palmer) was unable to wake him. He was declared dead on Wednesday night's episode.

Karim had been suffering from a brain tumour that had been removed.

Fans took to social media to express their outrage at the death of such a prominent and diverse character.

Some fans were particularly perturbed by the unexpected timing, saying: "You know Shortland Street has changed when they don't just kill a character at the end of the year, but a main character dies on a Tuesday night in April."

Another posted on Twitter: "What have we learned from Ali's death #shortlandstreet? Diversity is dead."

Others simply commented that they would no longer be watching.

One particularly fired up fan wrote: "Take your show...and f*** off. You lost a LOT of viewers tonight... Enough is enough. It ends here #RIPAli"

Others commented that they had been watching for decades, but would no longer be tuning in.

Shortland Street airs at 7pm weeknights on TVNZ 2.