Actor Ian Smith, famous for his role as Harold Bishop on Neighbours, announces terminal cancer diagnosis.

 The 86-year-old actor has announced he will depart from the popular Australian TV show after doctors diagnosed him with a form of lung cancer.

Beloved Neighbours star Ian Smith has revealed that he has been diagnosed with a "non-fixable" form of lung cancer.

The 86-year-old actor, best known for his role as Harold Bishop on the long-running Australian soap, shared his diagnosis in an emotional interview with Channel 10, announcing that he would be leaving the show.

Smith first appeared on Neighbours in 1987 as a love interest for Madge Mitchell, played by Anne Charleston, and has made five appearances throughout the years.

In his interview, Smith disclosed that he had been diagnosed with pulmonary pleomorphic carcinoma, a rare and aggressive type of lung cancer.

“I found out a few months ago that I have cancer — a very aggressive, non-fixable cancer, and they expect me to… they expect me to die,” Smith said.

He also expressed gratitude for his career, stating, “It isn’t just my last day on Neighbours, it’s my last day of work. I’ve had the most privileged life… we didn’t just make a soap, we made the best bloody soap there was to make. I have met the most beautiful people.”

Smith added that he had undergone three rounds of immunotherapy, a relatively new treatment, and was willing to participate in trials, saying, “I’ve really put my hand up to be a guinea pig. Plus the fact I don’t want to die, and I want to stay alive with quality for as long as I can.”

“I wake up every morning hoping there’s no pain, because I know that’s the beginning of the bad part. I’ve seen so many deaths. I’ve seen some good ones and some bad ones. I’m hoping I’ll go the nice way,” he continued.

Over the years, Smith’s character, Harold Bishop, became one of the longest-running roles on the show, with Smith staying on for 12 years from 1996. His most recent return was earlier this year, when it was announced that he would reprise the role in May.

"After fifteen years of living away, the legendary Harold Bishop is returning to Erinsborough," Neighbours tweeted, adding, "We are thrilled to welcome Ian Smith back to the show and the opening titles, where he belongs."

Smith's departure was reportedly filmed with farewell scenes, surrounded by co-stars, to explain his exit from the show.