Calgary Opera's decision to potentially cast a white person in an Asian role for "South Pacific" is generating backlash, with several cast and crew members quitting in protest.

The 1949 Richard Rodgers and Oscar Hammerstein musical deals with how racism affects two relationships on a South Pacific island during the Second World War.

Calgary Opera has had difficulty casting a Tonkinese character named Bloody Mary, so has considered filling the role with a white singer.

That decision led the musical's director and set designer, as well as a cast member, to resign in protest.

The former director of the Calgary performance says the themes of racial tension and tolerance are the main arcs of the story, and to have a white actor play the role would take away from the story's impact.

"I felt that it was really important to me as a director to honour the intention in the script of having that character portrayed by an artist of colour," said Mark Bellamy.

The brewing controversy in Calgary reflects an earlier incident in Edmonton, where a white woman was cast in the title role of “Othello.”

The production in Edmonton was cancelled before opening night after some cast members received threats over the casting.

Calgary Opera declined an on-camera interview with CTV News, instead issuing a statement detailing how hard it was to find a person of Tonkinese descent.

"In Canada and in the opera world, this combination is hard to come by, but we are ardently working on and committed to finding the voice and attributes that best suit the role," read the statement from Michael Brown, the opera's chair of the board.

Bellamy says the role has been performed for almost 70 years, and Calgary Opera's initial decision reflects a growing trend in the entertainment industry to turn to white actors and actresses to play roles intended for minorities.

"I think there's an ability to look beyond the world of opera to cast this role," he said.

The fear, Bellamy says, is this sort of casting leads to minorities feeling unwelcome and drives them away.

However, he says he is happy to hear the opera is still looking for other singers to play the role.

The musical is scheduled to be performed in Calgary Opera's outdoor Opera in the Village festival in August.

With a report from CTV Calgary's Kathy Le