In the new film Limbo, actor Rob Collins plays a man haunted by the disappearance of his sister from an outback town 20 years earlier.

His character Charlie believes police bungled the investigation, and when a world-weary cop (played by Simon Baker) turns up to review the case, Charlie doesn't trust him.

Collins says the character of Charlie was familiar to him.

"Very familiar," Collins says.

"Not so much my own experiences, but my family. I'm a Tiwi Islander and I don't think there's a single First Nations person that would look at the characters in Limbo and not have some sort of life experience of what the characters are going through."

Collins says Charlie and his family are "on the wrong side of the justice system".

"They've largely been forgotten, there's no justice for the family. There are wounds there that haven't healed over and have just kind of festered," he says.

"They're all familiar things with the Aboriginal experience, particularly when you're talking about its intersection with law and in Australia. I mean, it's an ugly truth, but that's the truth of that film and the truth of Charlie's experience.

"It was something that I instinctively felt that I knew."

It was a challenging role to play, Collins says, "mining those little pockets of hurt and angst, and regret and anxiety, and feelings of loneliness and isolation".

As the film progresses, Baker's policeman Travis offers Charlie a glimmer of hope for some sort of closure.

"And unfortunately for a lot of our mob, it's a closure they don't get to have," Collins says.

'Like a muffled scream'

Limbo is directed by Ivan Sen, best known for the films Mystery Road, Goldstone and Beneath Clouds. It also stars Natasha Wanganeen as Emma, Charlie's surviving sister, and Nicholas Hope as Joseph, the brother of a key murder suspect.

The film was shot in the South Australian opal mining town of Coober Pedy, which stands in for the fictional town of Limbo.

Sen's decision to film in black and white accentuates Coober Pedy's otherworldliness, making the pockmarked desert look like a moonscape.

Collins says he can't imagine filming the story anywhere else.

"The whole place feels like a muffled scream, which worked a lot for Charlie," he says.

"I love Coober Pedy but it has that sense of impermanence. It kind of reminded me when I got too comfortable that I actually shouldn't be there.

"It's so sparse and flat and alien."

Collins says Sen helped set the tone for his restrained performance in Limbo by telling him, "you're in a western".

"That was a penny drop moment for me," Collins says.

"Just by saying that one phrase, it kind of made clear to me how to respond, how to act, when to show emotion, when to conceal it. That was a big turning point for me."

He says knowing the film was being made in black and white helped. "Somehow the idea that it was black and white lent itself to that sense of restraint."

Collins shares almost all of his scenes with Baker, who he says was "exceptional" to work with.

"I found him warm and generous, as a person and as an actor.

"I learned so much from being with him and then watching him work."

'Our focus as a nation has shifted'

Collins would have to be one of Australia's busiest actors.

Apart from starring in Limbo, which airs this weekend on the ABC, he's currently appearing opposite Catherine Tate in the comedy series Queen of Oz, as a vampire hunter in Firebite (also filmed in Coober Pedy), and in the British production Ten Pound Poms.

He's just finished filming the new season of medical drama RFDS, and is currently making the third and final season of Total Control, the ABC drama about an Indigenous politician.

He says he's going to miss working on Total Control when it finishes.

"I don't think I have seen the kind of show that we're making on TV in Australia," he says.