Renowned New Zealand writer Dame Fiona Kidman has added another trophy to her cabinet after scooping the top prize at the country's annual crime writing awards.

Kidman's This Mortal Boy won the best novel at the Ngaio Marsh Awards in Christchurch on Saturday. The story is a recreation of the circumstances surrounding young Belfast immigrant Albert "Paddy" Black becoming the penultimate person hanged in New Zealand.

The book became the first to win both the Ngaio Marsh Award and the Acorn Prize for Fiction. It has also won the NZ Booklovers Award and the NZSA Heritage Book Award.

Judges said despite the historical nature of the novel, the spirit still resonated with regards to bigotry and discrimination.

"The quality of the writing is extraordinary, a richly textured sense of 1950s New Zealand and an elegant structure and flow creating a harrowing tale full of humanity."

Judges said it was a tragic story approached with sincerity and compassion.

"There was a sense of understated rage at the injustice of it all. Dennett has, with compassion and respect, shown us the young woman who was so much more than a 'teen prostitute' who went missing from K Road."

JP Pomare, who grew up on a horse farm near Rotorua and now lives in Melbourne, won the best first novel award for Call Me Evie, a mind-bending psychological thriller about a Melbourne teenager who is recovering from a traumatic incident in a remote cabin in Maketu.

Judges described Pomare's writing as "evocative and elegant".

"An intricate story packed with suspense and a fascinating exploration of the concept of false memory."

Kidman received a trophy, a special edition of a Marsh book, $1000 courtesy of Word Christchurch. Pomare and Dennett won a trophy, book and a cash prize.