Ande Cunningham is used to the physical challenges that acting brings. Playing the gladiator Duro in the historical drama Spartacus: Blood And Sand tested his physical strength and involved weeks of training in sword fighting and combat.

His latest role, however, brought more mental challenges than physical ones. Cunningham plays Palmerston North fraud detective Brent Garner in the TV One Sunday Theatre Venus And Mars, based on a real New Zealand case.

In October 1996, Brent was allegedly attacked and his home burned down in an apparently satanic police-targeted hate crime. Operation Venus was launched to find Brent's attacker – that was until his colleagues began to suspect Brent of committing the crime and the secret Operation Mars began.

Ande Cunningham as Detective Brent Garner.

READ MORE: Manawatu 'Satanic attack' re-enacted for docu-drama

A successful detective and family man on the surface, Brent's colleagues discovered that he had a darker side. "I was told the story very briefly and I found it pretty damn interesting," Cunningham says. "It is probably the most interesting role I've had yet professionally. A character like that is kind of a mystery you know? We've spent a lot of time talking about it and solving his motivations and all the aspects to his psychology."

Cunningham and executive producer Philly de Lacey worked together to try to understand how Brent was able to deceive his loved ones, inflict wounds on his body, bind and gag himself, and set fire to his home. "There's a few things about Garner that are interesting," de Lacey says. "I think there's obviously a level of arrogance to him that he thought he could pull this off. If he had gotten away with it ostensibly he would have got an insurance claim. He would have, if he had followed through, left his family and gone and started a new life. But I think he sort of assumed he wasn't hurting anyone. For all he knew the family were out of the house, they were safe, he was burning down his own house, it was him that he was hurting." Cunningham agrees. "I think that's the way he saw it and I think if he actually did hurt somebody, he'd probably be quite mortified. He probably just didn't realise what the aftermath was going to be."

To play Brent, however, Cunningham did have to go to dark places – especially while filming the crime. "I spent a lot of time in cable ties," he says. "I was gagged as well, and that's very uncomfortable, and a very strong capable stunt man was fighting with me and he was very careful, but you're pretty vulnerable."

Although the story sounds extraordinary, the drama is based entirely on fact. De Lacey says she never forgot while making the drama that the case involves real-life people. "It adds a real layer of responsibility," she says. "There's 20 years that have passed but there's still a lot of people who feel emotionally involved in what happened – which is obviously family members and there are actually still a lot of cops who feel really passionate about this case. That gives you an obligation to really try to tell the truth, you know, and that's been really important to us. You do have an obligation to the people who were there and who were part of it, to tell these stories properly, because they are the ones who are going to relive it and be asked about it the next day."

Also important to de Lacey and Cunningham was the idea that the case was not purely black and white. "I don't think he is fundamentally evil," de Lacey says of Brent. "I think he's someone who got consumed with an idea and he bought into it and committed to it and it didn't turn out like he wanted. I think actually, ultimately, it's really sad because I think he did care about his kids. I genuinely believe that. Like anyone I guess who does something pretty horrific, they have their downfall, but they're not generally all bad. They're complex, a mix of all sorts of things."

"And that's the thing," Cunningham says, "In fiction a character's motivation tends to be quite singular while a story like this, there's all these factors that come into play. That's why it's so exciting (to play). It's a very nuanced and contradictory character."

Venus And Mars, Tv One, Sunday

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