Oscar winner Eva Orner is on a mission. The Australian filmmaker left the success she was having in the US to spend two years touring the world's refugee camps and political hot spots with a camera, co-ordinating whistleblowers to shoot secret footage inside the Nauru and Manus Island detention centres.

Now Orner is spending six weeks travelling the country – launching the incendiary documentary Chasing Asylum and a book about its making – to urge Australians to call for the scrapping of what she considers cruel and immoral policies on asylum seekers.

"I thought I needed to make a film to shame Australia internationally and also to educate people in Australia about what's happening," she says passionately.

That education is necessary given the secrecy surrounding the country's treatment of asylum seekers and the complexity of the issue.

How do we make sense of the drownings at sea, the policy of stopping the boats and troubling reports of distressed refugees setting themselves alight or needing an abortion after a rape at an offshore detention centre?

Should we show compassion to people fleeing persecution, to children locked up for years, or are we best to trust the federal government is protecting our borders through mandatory offshore detention?

Orner pondered such questions while forging a career in New York then Los Angeles. Within three years of heading overseas in 2004, she had produced a documentary about torture by the US military, Alex Gibney's Taxi to the Dark Side, that won her both an Oscar and an Emmy.

She had made other documentaries too: Herbie Hancock: Possibilities, on the famous jazz musician, and two with the prolific Gibney – The Human Behaviour Experiments and Gonzo: The Life And Work Of Dr Hunter S. Thompson.

Then Orner moved into directing with The Network, a behind-the-scenes documentary about a TV station in Afghanistan.

That was a huge jump from her work in Australia – production manager on such TV series as Blue Heelers and The Games and producing the little-seen films Strange Fits of Passion and Josh Jarman.

But Orner was simmering as she watched the country's handling of refugees from afar, expecting someone else to make a film about it then realising she had to do it herself. "Anger and frustration" were the motivation behind Chasing Asylum, which she funded entirely with private donations – with no government or broadcaster backing.

Shooting it – following refugees in Indonesia, Cambodia, Lebanon, Iran, Afghanistan and Australia over 18 months – was a brutal experience.

"It was hard, man," Orner says. "I've been making films for over 20 years – a lot of tough films – and this was by far the hardest. It was the most personal.

"The heroes of the film are obviously the refugees and the asylum seekers but also the whistleblowers, who were so brave. Without them, we wouldn't know what's happening.

"Along the way, you see lives have been destroyed. Refugees and asylum seekers have been so damaged by what they've been through.

"And every whistleblower I met was suffering some kind of trauma from their time working in the camps. You just see so many damaged people along the way from our policies."

The documentary earned a rare glowing endorsement in an editorial in Melbourne's The Age last week that praised Orner's courage. "We urge citizens to see the documentary," it read. "We believe it will convince most of them our lawmakers must evolve their policies."

So who is this crusader? And why does she care so much that she wants to shake the country into action?

Orner, 46, grew up in Melbourne's Brighton. Her mother studied biochemistry at Melbourne University; her father, who never finished high school, became an apprentice toolmaker then built a successful automotive engineering business.

With older brother Michael, she had what she calls "a great Australian childhood", attending the Jewish school Mount Scopus Memorial College before studying arts at Monash University. While she considers herself non-practising, her family's Jewish background left a powerful impression on her view of the world.

With three out of four grandparents dying during the Holocaust, Orner's Polish-born parents were welcomed to Australia as post-war immigrants.

"It's always been an issue very close to my heart as a first-generation Australian and a child of a family that was pretty devastated by the Holocaust," she says. "My parents were both born in 1937 – Poland, Jewish – so I was brought up with a pretty strong sense that terrible things happen to good people and that people are often in situations where they need help and support and kindness and generosity."

Orner fell in love with film after university.

"By the time I was 24, I'd made my first documentary – producing Sarah Barton's Untold Desires, about people with physical disabilities and sexuality, that won an AFI, Logie and Human Rights award. By then I couldn't look back."

She went to the States to work in a bigger pool.

"I wanted to stretch my wings," she says. "I ended up in New York and working with Alex Gibney, which was pretty great."

While Michael Moore's Sicko had been favourite, Taxi to the Dark Side gave Orner an Oscar.

"It was a film that was really important at the time and is still considered important and relevant," she says. "And, on a really fun level, it was crazy and surreal. It's really funny that I have an Oscar in my house."

Seeing the footage secretly shot by whistleblowers on the Manus Island and Nauru detention centres, Orner is appalled by the asylum seekers' living conditions.

"It's shocking," she says. "The fact that we're paying $1.2 billion to keep a couple of thousand people living in squalor is shameful.

"People are living in tents that are mouldy. They have sub-standard food. Their children have no access to things needed for development in childhood like freedom and space and privacy and toys and games and proper education."

Orner blames successive Australian government for "a very harsh, secretive policy" on asylum seekers for 15 years.

"The biggest disappointment for me in Australian politics is that our two major parties have virtually the same policies when it comes to refugees and asylum seekers."

The way forward, she believes, is shown by former prime minister Malcolm Fraser's actions when boats were arriving from Vietnam in the seventies and early eighties.

"He set up processing camps in Malaysia, it took six to eight weeks for people to be processed then they were flown to Australia to avoid deaths at sea."

She believes proper processing of applications is not only possible, it's essential.

"If we set up proper processing centres and we process people, the system works beautifully," she says. "We just need to have proper screenings – efficient and fast and adequate."

Orner says Australia ranks a lowly 67th in the world for refugee intake, taking 13,750 a year, which she considers mean spirited. (Although the Abbott government announced a one-off take-up of 12,000 Syrians, she says fewer than 100 have been resettled.)

"The big argument from people is 'what do you want to do, let everyone in?' No one is saying that.

"I'd say let's take in 50,000 a year. We have a low population, we have a lot of space, we have low unemployment.

"Bring people in, teach them the language, educate them in our customs, let them become part of our multicultural society and let us be the beneficiaries of what they can offer us instead of spending $1.2 billion a year torturing and, in some cases, damaging and killing people."

Orner believes the plight of asylum seekers in detention should be an issue in the federal election.

"Its heartbreaking," she says. "That's not who we are and not who we want to be. At some point we've got to stand up. It's got to stop."

Chasing Asylum opens on May 26. The book Chasing Asylum – A Filmmaker's Story (Harper Collins, $29.99) is out now.

Correction: An earlier version of this story stated that Eva Orner's parents were born in 1947.