Only the Australian public paying attention to the horrors in offshore immigration detention can change government policy, the Australian human rights commissioner has said.

The commissioner, Gillian Triggs, was addressing the Nauru files, a cache of more than 2,000 leaked documents from inside Australia’s offshore immigration processing centre on Nauru.

The documents, published by the Guardian on Wednesday, has revealed the extent of abuses and trauma on the island over a 26-month period and reaction from the public, human rights organisations and politicians was swift, including calls for a royal commission.

Triggs told ABC radio the report backed up what the Human Rights Commission had tried to tell the parliament with its own review into children in detention two years ago.

Asked if her report was now vindicated, Triggs said: “We rely very heavily on the media to report these facts and ensure the public is accurately informed, and I think that’s the case here.

“We really need to public’s attention to ensure that our politicians change the policy. This is unsustainable, and of course extremely expensive to the Australian taxpayer.”

If media had access to the immigration centres, the Australian public could be moved in the same way they were over the Don Dale juvenile detention abuses broadcast last month.

“Our democratic system depends on transparency and access by our journalists and also by other community groups who can speak up and take photographs. That is what really moves the public, when they actually see, preferably on video, how these children are being treated.”

Elaine Pearson, the Australian director of Human Rights Watch, said the Don Dale images shocked the Turnbull government into action, and called for the same in response to the evidence presented in the Nauru files and in other investigations.

“The fact that the number of serious incidents has not declined but continued steadily, and in some cases escalated, is further proof that the failure to address abuses is a deliberate policy of the Australian government to deter further boat arrivals,” Pearson told Guardian Australia.

“Australia’s policy of deterrence is premised on making people in offshore locations suffer. This policy is inhumane and irresponsible, and it means refugees and asylum seekers remain vulnerable to further abuse and mistreatment. Men, women and children need to be removed from Nauru immediately.”

On social media, many people reacted with shock, others with frustration and anger that the government stands by its policy despite frequent revelations about conditions on the island.

Sean Kelly (@mrseankelly) Files from Nauru. What line, exactly, are we waiting to cross before things change? https://t.co/9KlYMug9Tn pic.twitter.com/u6hQSB1Tho

Michelle Bennett (@mm_bennett) When reading the #naurufiles remember the #whistleblowers who took the risk to reveal the shocking abuse of children https://t.co/OEML2ioMc8

David Lipson (@davidlipson) Our national shame. Stopping boats is important but we must find another way. At very least we need transparency. https://t.co/qBH3Qnpr7V

Amnesty Victoria (@Amnesty_VIC) The need to pressure the government to close offshore detention centers has never been higher #naurufileshttps://t.co/SiEnBesW2U

ChilOut Revived (@ChilOutRevived) Planning protest actions re #NauruFiles? Pls send us direct message@riserefugee @rar_australia @rac_sydney @Mums4Refugees @grandmothersref

Anna Neistat, senior director for research at Amnesty International, said the leak “laid bare a system of ‘routine dysfunction and cruelty’ that is at once dizzying in its scale and utterly damning for the Australian authorities who tried so hard to maintain a veil of secrecy.”

Neistat recently went undercover to the island to investigate the treatment and living conditions of detainees, and called for the end of government denials.

“The Australian government has engaged in one of the most successful mass cover-ups I’ve witnessed in my career of documenting human rights violations,” she said.

The opposition defence spokesman, Richard Marles, said the Guardian’s reports were concerning, and said Labor had argued for independent oversight of the centres, reopened under their government, to maintain transparency.

“The first point that really needs to be made is Australia has obligations in relation to facility on Nauru – those obligations should be ensuring that these facilities provide safe, dignified, humane refuge to the people within them,” he said.

Australia fails the same lesson every time. The Nauru files show how secrecy hides abuse | Kristina Keneally Read more

“We have been very critical of the government’s lack of transparency in the running of Nauru over the last couple of years.”

Marles denied oversight was prevented by the facilities being located in foreign jurisdictions, because the government “could be talking to Nauru to ensure independent oversight”.

“It’s not clear to me those conversations have ever occurred around that question,” he said. “You could put in place mandatory reporting of child abuse – as we sought to do through private member’s bills in the Australian parliament – so there are steps that can be taken here”.

Marles said it was important that “people be gotten off Nauru”.

“There need to be third country options found for those on Nauru and Manus, and in that the government has wholly failed,” he said.

“Of course, as people’s uncertainty continues, as hope is removed, you’re going to see increasing acts of desperation. The government needs to get on its skates and find third country resettlement options for those on Nauru and Manus.”

The shadow assistant treasurer, Andrew Leigh, told Guardian Australia he was “shocked by what I’ve seen” in the Nauru files reports.

“We’ve had range of independent reports, and I’ve talked to people from the UNHCR – we know people on both Nauru and Manus Island are deeply traumatised now.

“We need to get them off Manus and Nauru, they have been waiting over three years to be resettled so you can understand why they are in such terrible shape.”

Leigh said the government’s inability to conclude a third country processing arrangement had resulted in poor physical and mental health of asylum seekers, leaving them “amongst the most traumatised in the world” despite the flow of people to Australia being small by world standards.

“That’s a population that includes refugees of the Assad regime who have been barrel-bombed,” he said.

Asked what the government could do other than resettle them elsewhere, Leigh replied: “Anything short of third party settlement is inadequate for what these people need.”

A refugee activism group called for an immediate public inquiry into the centres and for all detainees to be transferred to Australia or a third country.

Pamela Curr, from Australian Women in Support of Women on Nauru, which recently released their own report into the treatment of women on the island, said the situation was so dire “only a royal commission could get to the bottom of the systemic abuse experienced by women, children and men in these camps”.

“Our politicians know all about this – the broader community may be kept in the dark but both Labor the Coalition know all about this and their silence is taken as consent,” Curr said.

Hugh de Kretser, the executive director of the Human Rights Law Centre, told Guardian Australia: “Nothing excuses the failure to act. There is a real hypocrisy in the fact we have two royal commissions currently afoot – one into institutional child sexual abuse and another into youth detention centres – and yet at the very same time we’re warehousing children on Nauru in conditions that allow this kind of abuse to thrive.”

De Kretser said there needed to be a full inquiry but the safety of people on the islands or at risk of being sent to the islands was the first priority.

“We have the evidence now and the first thing the government has to do is act on that evidence and bring these people here to safety.”