J. K. ROWLING has given a strong hint that two of her main characters in the Harry Potter books, Hermione Granger and Ron Weasley, would become an item in the final instalment of the series.

The author told a New York audience that Hermione, based on herself, wanted an intimate relationship with a boy she knew well. If she looked in the Mirror of Erised, which shows one’s deepest desire, she would “see herself entwined with another person whose identity you can probably guess”.

Herminone and Ron have been the Lizzie Bennett and Mr Darcy of Hogwarts for several volumes of the seven-volume series.

Rowling laughed off the suggestion, by some fans, that Hermione would fall in love with Harry. “There are people who wanted Harry and Hermione,” she said, to cheers from the audience at Radio City Music Hall. “They’re still out there.”

John Irving, the American author of The World According to Garp and The Cider House Rules, and Stephen King, the horror novelist, told a press conference that they wanted Rowling to be lenient after reports that she may kill Harry off. Irving said that his “fingers are crossed for Harry”.

King hoped that Rowling would not emulate Arthur Conan Doyle, who killed Sherlock Holmes. “I don’t want him to go over the Reichenbach Falls,” he said. Conan Doyle had his detective die because he was tired of writing about him, but revived him after a few years.

In a separate development Helena Bonham Carter was named as a villain in the next Harry Potter film. She will play Bellatrix Lestrange, a death eater, in Harry Potter and the Order of the Phoenix. Imelda Staunton will play Dolores Umbridge, teacher of the dark arts.

The fifth big-screen Potter adaptation is being directed by the award-winning British film-maker David Yates, whose movies include The Girl in the Café, Sex Traffic and State of Play.

Daniel Radcliffe (Harry), Rupert Grint (Ron) and Emma Watson (Hermione) will reprise their roles as the teen wizards, and regulars such as Robbie Coltrane, Michael Gambon, Ralph Fiennes, Gary Oldman, Alan Rickman, Maggie Smith, Emma Thompson and Julie Walters will reappear.

George Harris, who was recently a gangster in Layer Cake, will play Kingsley Shacklebolt, a member of the Order of the Phoenix. Natalia Tena is Nymphadora Tonks, Kathryn Hunter is Mrs Arabella Figg and Evanna Lynch, 14, is Luna Lovegood.

The film, which will have a score by Nicholas Hooper, is being released next year.

The film franchise has made £1.9 billion at the box office and its principal actors are multimillionaires. Daniel Radcliffe has amassed a fortune of £14 million, according to The Sunday Times Rich List. Rowling, who will not publish the last instalment before next year, is worth about £520 million.

She said recently that she had changed her planned ending so that one character survived the series, but another much-loved hero would face the chop. “I have to say that two [characters] die that I didn’t intend to die . . . A price has to be paid. We are dealing with pure evil here. They don’t target extras, do they? They go for the main characters.”