Louise Nicholas, left, and the actress playing her in Consent, Michelle Blundell.

Louise Nicholas' harrowing story of abuse will screen next week as part of a dramatic retelling of New Zealand's highest profile rape case.

It features teenage actress Thomasin Harcourt-McKenzie, daughter of actress Miranda Harcourt and grand-daughter of actress Dame Kate Harcourt.

They kick off the ugly back story when Nicholas sought help from Rotorua CIB boss Detective Inspector John Dewar after she was attacked.

Nicholas told the Herald on Sunday the hardest part of watching the movie was not the rape scene but another scene where she tells her children about what she went through.

"My girls are my strength, they have taken everything that has happened in the last 10 years and turned it into something positive. They have really amazed me and they are mini-ambassadors.

"They were there when everything was unfolding and how it affected them was the hardest part. Reliving it, was harder again."

The story told in Consent which screens on TVOne next Sunday centres on the relationship between Nicholas and Dewar, who betrayed her by covering for his colleagues while Nicholas believed he was the only one she could trust.

A launch event is being held in Wellington next Friday and Justice Minister Judith Collins, Social Development Minister Paula Bennett and Police Commissioner Mike Bush will be there.

Dr Kim McGregor, executive director of Rape Crisis, said the story was vital in continuing to expose New Zealand's rape culture.

"Because of the bravery of many survivors of sexual violence such as Louise and others... the general public will no longer tolerate it when cases of sexual violence, such as the so-called Roast Busters case, come to light."

The tele-movie follows Nicholas as Dewar obstructs justice at trials, through years of failure to be heard until help from journalist Phil Kitchin.

Five trials and 20 years later Nicholas' testimony led to the Commission of Inquiry into Police Conduct which resulted in the damning 2007 Bazley Report.

Former police officers Brad Shipton and Bob Schollum, and Assistant Commissioner Clint Rickards were found not guilty of Nicholas' rape, though Shipton and Schollum were already behind bars for the rape of another woman.

Dewar was convicted of four charges attempting to obstruct or defeat the course of justice and jailed for four and a half years.

Consent also features scenes where the trio are involved in sex with her, events which all three claimed during their trials were consensual.

The movie was created by the team behind Out of the Blue - the story of the Aramoana massacre.

Nicholas, who now works for Rape Prevention Education, said the movie brought her smiles and tears.

"I don't want anybody else to go through what I did.

"One of my greatest lessons has been that these are individuals who hurt me, not an organisation. I am also pleased that it didn't turn into police-bashing, for me it was important that that didn't happen."

Consent: The Louise Nicholas Story is on TVOne's Sunday Theatre at 8.30pm on August 17.

Rape Crisis will run a special telephone support line immediately after the drama.