A campaign backed by independent politicians including Kylea Tink is calling for a comprehensive investigation of the long-standing bipartisan policy.
Kurdish artist and musician Farhad Bandesh, who came to Australia by boat after fleeing political persecution in Iran, was held for six years on Manus Island in Papua New Guinea.
Farhad Bandesh says he was beaten and denied basic necessities while held on Manus Island. (HANDOUT/WENDYHOUSE FILMS)
He recounted being beaten, denied basic necessities and, for two years, bleeding continuously as detention centre staff refused him medical attention.
"This whole system is cruel and wants everybody to be silent - they tried to bury us alive," he told AAP.
Mr Bandesh, 41, witnessed the murder of Kurdish asylum-seeker Reza Barati at the hands of security guards after a riot in 2014.
Fourteen asylum seekers have died in offshore detention centres over the last decade, including several deaths from self harm.
"This came from the top starting with the Australian government to doctors, nurses and security staff to put pressure on us, to make us crazy and drive us mad," Mr Bandesh said.
He was later detained in a Melbourne hotel for 16 months after coming to the mainland for medical treatment.
Mr Bandesh was eventually freed on his birthday in December 2020.
Julie Macken from the Catholic Archdiocese of Sydney's Justice and Peace Office is helping co-ordinate the royal commission campaign.
A public event will take place at Parliament House in Canberra on Tuesday.
"Almost no policy has changed Australia as much as the immigration policy settings have over the last 25 years," Dr Macken said.
"Australians have actually got a right to know what is being done in our name."
For years, the Liberal and Labor parties have presented offshore immigration detention as a key plank of border protection.
Dr Macken said a royal commission was needed in order to compel private security firms tasked with running offshore detention centres to produce documents outlining their lucrative government contracts.
She said the commission would also allow former detainees and centre staff to give evidence without fear.
Reza Berati was killed by security guards after a riot on Manus Island in 2014. (Dan Peled/AAP PHOTOS)
The royal commission calls are set against an intense focus on immigration detention.
The High Court recently ruled indefinite detention unlawful, with federal parliament passing emergency laws to keep track of people released as a result.
As well, a coronial inquest is underway into the deaths of three inmates at Villawood, an onshore immigration detention centre in Sydney.
Home Affairs secretary Michael Pezzullo, who for years was the public servant in charge of administering immigration detention, was this week sacked from his powerful role.
Mr Pezzullo was fired over a code of conduct breach after leaked text messages showed he repeatedly inserted himself into the political process, in breach of public service rules.
"They (Labor) have inherited an absolute basket case of a department (Home Affairs) and a dog's breakfast of policy," Dr Macken said.
"All they need, frankly, is the leadership and the humility to say 'we're in a hole, let's stop digging'."
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