Immersed in a dog-eared paperback in his private trailer, LaPaglia is happy to share his views about the controversial WikiLeaks founder. He believes that far from being the traitor that many world leaders insist him to be, Assange is a beacon of light for exposing sensitive military secrets the public has the right to know about.

The Adelaide-born actor, who has spent most of the past two decades working in the US, proffers his own list of traitors who deserve to be put on trial for war crimes. It's a list that includes senior figures of past and present US governments.

LaPaglia says he would love to meet and talk to Assange; so, too - albeit for entirely different reasons - does Detective Ken Roberts, LaPaglia's character in Underground: The Julian Assange Story.

Roberts is a shaggy cop who's about to discover just how ill-equipped he is to tackle the new frontier of cyber crime. The irony of playing Assange's would-be nemesis isn't lost on LaPaglia.

With a blockbuster movie still years away - last year Steven Spielberg acquired the rights to WikiLeaks: Inside Julian Assange's War on Secrecy by Guardian journalists David Leigh and Luke Harding - Matchbox Pictures was interested in developing a quick-turnaround film about Assange.

To circumvent the thorny legal issues that surround Assange, who is holed up in the Ecuadorean embassy in London, the producers decided to focus on a pivotal two-year span of his teenage years, a period defined by momentous events in Assange's personal life and his initiation into the clandestine world of computer hacking.

As documented in Suelette Dreyfus' 1997 book Underground: Tales of Hacking, Madness and Obsession on the Electronic Frontier, Assange, using the pseudonym Mendax, first came to the attention of authorities in the late 1980s, when he and a posse of international hackers infiltrated what were supposed to be secure websites.

As the film tells it, their modus operandi was to look around but not steal anything. But having stumbled upon military intelligence that anticipated the civilian casualties of the first Gulf War, the experience galvanised Assange into his next act.

Writ large in this small slice of Assange's life are the larger themes that dominate the current debates about him and WikiLeaks.

For LaPaglia, Underground is an opportunity for audiences to engage with a perspective that challenges the one-sided profiles that have emerged since Assange went into hiding following the publication of classified Pentagon material and allegations of sex offences in Sweden, for which formal charges are yet to be made.

Playing Assange is newcomer Alex Williams, who landed the role after his first audition since graduating from the Western Australian Academy of Performing Arts at the end of last year. With his cleanly parted fair hair and soft voice, Williams bears an uncanny resemblance to Assange.

To portray him, Williams wanted to understand as much as he could about Assange's activities as a fledgling hacker. But he also wanted to detach himself from the contemporary figure.

''There's another 20 years of hacking and going around the world, dealing with journalists and governments,'' Williams says. ''He's much freer in this. I didn't want to play a 20-year-old or 40-year-old Julian Assange, I just wanted to play him as a teenager.''

Assange, he says, was ''an intense dude'' who saw the internet as a ''whole new frontier of exploration''.

Unlike the stereotype of computer buffs as nerdy, friendless misfits, he and his fellow hackers were regarded as cool - the punks of their day.

Rachel Griffiths, who plays Assange's mother, Christine, has little doubt of the defining role his mother played in nurturing his rebelliousness and moral backbone. Assange's itinerant childhood was anything but conventional or cosseted, and Griffiths believes the young Assange was inspired by the activism of his mother, who was a vocal opponent of the Vietnam War and the nuclear arms race. She, in turn, was impressed with his developing political conscience.

''There's part of her that's the true believer, but the argument that [attending rallies] is not a powerful way to lobby must have crossed her mind,'' Griffiths says. ''I think she's in awe of the possibilities … of a world where you can tweet a revolution, and in which it's becoming increasingly hard for people to hide what they're doing.''

Griffiths has a clear memory of what she thought the first time she heard of Assange: ''That guy must have an interesting mother.

''I viewed him with this kind of psychological curiosity. What makes a man like that? I thought, that man doesn't have a father and must have an interesting mother because there is some intrinsic molecular revulsion of authority in that man. It's compulsive. It's in his DNA.''

Unsurprisingly, in light of the headlines that the Assange matter continues to generate, Underground has attracted considerable interest around the globe. Unusually for a telemovie that was made in only five weeks on the smell of an oily rag, it was invited to screen at the recent Toronto International Film Festival, where it was well received by critics.

For Channel Ten, it promises to be a much-needed salve from the drubbing its latest batch of low-rent reality shows have received, while for viewers, it's a challenge to the widespread perception of Assange as a cold, callous - and possibly immoral - whistleblower with a chequered past.

''What I like about doing this film,'' Williams says, ''is that most people won't see any of this portrayed in the news or by a journalist writing a story.''

Q&A with Rachel Griffiths

What did you make of Underground when you read the script?

It's really quite a critical study for me. Apart from the giant question, which was there from the moment Julian stepped onto the world stage - which is ''What makes a man like that?'' - it's very clever. It's not trying to tell a big story. It's a fragment of a biography. It focuses on a critical point.

What did it tell you about how much activism has changed?

For me, sociologically and historically, what's interesting is the schism in time between an organic and analog activism, represented by Christine parading outside an embassy trying to draw attention to what she feels is a wrong, and reaching what Julian sees, in the movie, as a certain kind of futility, the energy of the baby-boomer optimism waning in its ageing years - the voices aren't as clear, the feelings between people to create protest aren't as strong. A point where he recognises a new activism of information in a digital age.

You have protested yourself against gambling in Melbourne.

I did an incredibly analog protest at Crown. It couldn't have been more analog. [That was] old-school protesting. It goes back to the mediaeval girl on a white horse, naked, protesting a tax. It's ancient and it's very female because it requires community. It uses voice and body and organisation. But in this moment, in Julian's mind's eye, the future that he can see is one where the power to protest lies in disseminating information and using it against those that want to keep it.

Do you think it works?

If we move forward to the Arab Spring, to how Twitter is being used in Iran, to non-traceable satellite phone technology being used so massacres in Syria cannot be kept from either the West or their own people, it's been a more powerful tool. It's destroying secrecy. How many boys are being liberated because they're finding out they weren't the only one being molested by their parish priest? I think that is so positive. It's very masculine, it's digital, unemotional and it's the strength and weakness of Julian. I don't … believe all information should be in the public arena, but who decides? Who has that power?

Underground preview - Sunday, 7.30pm

THIS deftly drawn portrait of the hacker as a young man features a canny combination of ingredients. Blending family drama, teen romance and cop thriller, it creates a nuanced profile of one of the most controversial figures of the 21st century.

Fixing its focus firmly on Julian Assange's early life and formative experiences, it explores the forces that shaped his view of the world and sense of place in it, tracing his development from a watchful boy to an adult driven by unshakeable resolve.

Part of the considerable pleasure of watching Underground comes from director Robert Connolly's adept juggling of a range of elements into such a compact yet cohesive package. Assange's relationship with his mother, Christine (Rachel Griffiths), is economically and evocatively drawn, as is his relationship with his first love, Electra (Laura Wheelwright).

Yet the film also zips along as a thriller, re-creating the cat-and-mouse games that a cocky, adolescent Assange and his computer-savvy mates played with the local police and, beyond them, unseen in the wings here, the US government.

Connolly cleverly evokes the thrill of the chase from the hackers' point of view: the heady buzz of believing you're the smartest guys in the room, the sense of being one nimble step ahead of the plodding pack in the brave new world of the internet.

In this case the pack, represented primarily by Detective Ken Roberts (Anthony LaPaglia), is seen as a slightly anachronistic force, solid when it comes to old-fashioned police work but needing to have the concept of a modem explained. The scene in which a cheeky Assange shows off his command of the new world by setting the phones in the police squad room ringing is a joy.

Casting also plays a key role in the film's success. Alex Williams, a recent drama school graduate, delivers a disciplined and potent performance as Assange; Griffiths and LaPaglia flesh out fully formed characters with scant screen time; and Wheelwright brings real spark to Electra.

Following Channel Ten's recent horror run, it's heartening to see the network involved in such an accomplished local drama.

DEBI ENKER