JK Rowling has backed a new scheme aimed at discovering female crime writers from black, Asian, minority ethnic (BAME) and working-class backgrounds, hoping that it will help “open doors to new and as yet undiscovered voices in crime fiction”.

Killer Women, an author collective of 20 female crime writers, opens its new mentoring scheme on Wednesday for unpublished women from under-represented backgrounds who want to write crime or thriller novels. Entrants must submit a synopsis and sample chapters of their writing and the four winners will receive mentoring and support from writers including the award-winning Jane Casey, author of the Maeve Kerrigan series, and Emma Kavanagh, a police and military psychologist turned crime author.

Rowling said: “For me, writing crime fiction behind the pseudonym Robert Galbraith was a way to ensure that my books be judged on the merit of the writing alone, but I know how hard it is when you first hit the scene as an unrecognised author.”

Rowling’s Harry Potter books were turned down by 12 publishers before they ended up with Bloomsbury. When she submitted her first crime novel to publishers under a pseudonym, she was told by one that it could not be published with “commercial success”, and advised her to try a writing course.

The Killer Women scheme, backed with funding from Arts Council England, is also supported by authors including Val McDermid, currently the highest ranking female author on the crime charts, and Martina Cole.

“I grew up in a working-class home, well aware that people like me didn’t become writers. I was lucky enough to break out thanks to a first rate – free – university education, but when I started writing, I knew nobody in the publishing business,” said McDermid. “Restricting access impoverishes our culture, and I’m delighted and excited at this initiative from the accomplished and innovative Killer Women.”

Cole said it had taken her a “very long time” to find the confidence to fulfill her dream of becoming a published author. “My friends would say ‘working-class people like us don’t write books’,” she said. “It’s nearly 30 years ago but I can vividly remember how nervous I was at my first meetings with my publisher Headline. This was a completely new and alien world to me.”

Cole said that publishing had “changed enormously” and “there are more authors from diverse backgrounds being published”. “But I know to many writers trying to break through, it can still seem like an intimidating industry which is why the Killer Women mentoring scheme is so timely and I am delighted to support it,” she added.