The novelist JK Rowling has told an audience in Canada she is surprised by the amount of fuss generated by her announcement that one of the main characters in her Harry Potter series is gay.

The 42-year-old, whose seven-series saga about the boy wizard has made her an estimated £545m, sent shockwaves round the world on Saturday when she told an audience of fans in New York that the headmaster of wizarding school Hogwarts was gay.

“It has certainly never been news to me that a brave and brilliant man could love other men,” she told a news conference today in Toronto, according to Reuters.

The English-born writer, who lives in Scotland, defended herself against accusations that she is trying to push a pro-gay agenda on her younger fans.

“He is my character. He is what he is and I have the right to say what I say about him,” she said.

Ms Rowling also revealed that her revelation about Dumbledore had an unexpected and immediate outcome:

“I know that it was a positive thing that I said it, for at least one person, because one man ‘came out’ at Carnegie Hall,” Rowling told a news conference, according toThe Canadian Press.

Dumbledore, played in the Harry Potter films initially by the late Richard Harris and later by Michael Gambon, is killed in the sixth book in the series.

He makes a ghostly appearance in the seventh, where it is revealed that he fell under the spell of a charismatic but evil wizard, Gellert Grindelwald.

She described the infatuation as a key part of her convoluted plot and confirmed today that she knew that the Dumbledore was gay even before writing the first book.

Ms Rowling revealed Dumbledore’s homosexuality at a New York book reading last week when asked by a fan if he had ever found love.

Christian groups have attacked her for “promoting” homosexuality while gay activists are equally unhappy.

“We can only conclude that Dumbledore saw his homosexuality as shameful and inappropriate to mention among his colleagues and students,” wrote John Cloud on the Time magazine website.

“His silence suggests a lack of personal integrity that is completely out of character.”

Meanwhile Laurie Higgins, writing for Americans for Truth About Homosexuality, who describes herself as “working full-time in a suburban public high school writing centre in the Chicago area,” is concerned that the revelation poses a threat to children:

“Now some, perhaps many of the children who love this character will feel ambivalent about regarding homosexuality as deeply sinful.

“The movement is afoot to include positive portrayals of homosexuals and the transgendered in all textbooks from kindergarten on up.

“I have no objections to textbooks including the important invention or discovery of a homosexual or transgender person so long as their homosexuality or transgenderism is not mentioned.

“To mention it suggests that somehow their deviant sexual impulses are connected or relevant to their discovery, invention, or contribution to learning.

“And supporters of subversive sexuality know this. They know that associating the deviant sexual orientation or identity with something positive will irrationally transform society’s perception of the deviant sexuality.

“Concerned citizens must strenuously oppose the identification of the sexual orientation or sexual identity of figures discussed in textbooks.”