Social justice advocate Celia Lashlie's dying wish realised as new doco premieres on the big screen

The premiere of the documentary 'Celia' in Wellington last night fulfills a request of the late social equality advocate Celia Lashlie.

Three-and-a-half years after her final interview, recorded just three days before she died from pancreatic cancer, Ms Lashlie's straight-talking, compelling messages have been brought to the big screen.

The sold-out premiere for Celia was held as part of the New Zealand International Film Festival at the Embassy Theatre.

Journalist Amanda Millar was asked by Ms Lashlie to make a documentary on her life and key messages, shortly after she was diagnosed with terminal cancer.

"I want to do this documentary in order for others to continue the work that I've started and that I now can't finish," Ms Lashlie had told her.

"In her heart, she'd done the stuff with the boys but truly, her passion was was the plan to work with vulnerable families, especially women and try to change the outcome," Ms Millar told 1 NEWS.

Ms Millar had reported on Ms Lashlie's work over a period of 15 years, but called the documentary "the greatest assignment of my life".

"You can't say no when somebody says, 'Please, would you fulfill my dying wish?" she said.

Ms Lashlie was News Zealand's first female officer to work in a male prison.

She then managed Christchurch Women's Prison.

Afterwards, she turned to working with teenage boys and giving talks to parents around the country. For her best-selling book, He'll Be OK - Growing Gorgeous Boys Into Good Men, she held discussions with 180 boys' school classes.

Her final crusade, improving families by reducing domestic violence - working with mothers in particular - was work cut short.

"That's my thing, it is only in working with the mothers that we will get to save the lives of these children," Ms Lashlie said in her final interview.

"At the heart of my being is the plight of women. This society that we spend millions of dollars on benefits, millions of dollars trying to stop child abuse, billions of dollars trying to stop family violence and no one has said, 'Turn to the mothers.'"

The 61-year-old was told she had at least 12 months to live when she was diagnosed with cancer, but this was soon reduced to just a few weeks.

"We got an interview over an hour and a half and then two days later, she left us," Ms Millar said.

The plan for a documentary on the last year of her life was gone and Ms Millar questioned how the documentary could continue.

However, the single interview became the gripping centrepiece of the film, which also features moments throughout Ms Lashlie's life in archival footage, stories of personal impact from her work and interweaving tributes from others.

The next challenge was finding enough funding to complete her dying wish, with Ms Millar turning away from television network funding to "stay true" to how Ms Lashlie had envisioned the piece.

A Givealittle online fundraising campaign was launched and Ms Millar made the funding call on a radio segment.

Garry Robertson was listening and - as someone who believed in Ms Lashlie's morals and had attended one of her talks as a parent to boys - decided to help.

"My own mum was equally to blame for everything that went on at our house and it really struck a chord with me so I'm hoping we can use that and teach a lot of people," Mr Robertson said.

Mr Robertson paid the funding difference, becoming executive producer of the documentary.

It's hoped new audiences, from all walks of life, will learn from Ms Lashlie's raw approach through watching the film.

"Since she died, we missed her, I think people are craving her practical advice, her insight," Ms Millar said.

She said Ms Lashlie would be heartbroken to know that prisoner numbers have only increased since her death in February 2015. 

The film has already sold out in Wellington, Auckland and Christchurch, with extra screenings being added to the line-up.

Ms Millar said it's a future focus for the documentary to be used as a resource in communities where seeing the film at the cinemas isn’t an option.

The film premiered to a sold-out theatre in Wellington last night as part of the New Zealand International Film Festival. Source: 1 NEWS