Lawyers representing four asylum seekers have claimed a partial victory over the federal government after bringing legal action over alleged breaches of care in offshore detention.
The four asylum seekers had previously launched Federal Court legal action against the Home Affairs Minister, alleging the government did not give them adequate medical care while detained on Nauru.
The federal government appealed that the Federal Court, under Australia's Migration Act, did not have the jurisdiction to decide on those cases.
Wednesday's High Court judgement found the Migration Act did not prevent lower courts from hearing such matters.
Lawyers for asylum seekers argue this ruling means similar cases covering as many as 50 refugees and asylum seekers can now be heard in state courts and the Federal Court.
In a statement, the National Justice Project claimed the ruling was a "major legal victory" against Home Affairs Minister Peter Dutton.
National Justice Project senior solicitor Anna Talbot said the judgement marked a victory for refugees and asylum seekers wanting to hold the government to account for their time in offshore detention.
“We see this as a complete repudiation of the government’s attempt to thwart asylum seekers and refugees holding it accountable for the harm that it has caused them by sending them to Nauru and Papua New Guinea,” she told SBS News.
“To have wasted two-years of our clients' time after causing them unnecessary harm and injury is just a tragedy.”
Ms Talbot said the government's appeal had threatened to make the cases more expensive and result in them taking more time to be resolved.
"There was no need for the High Court to be involved in these cases whatsoever," Ms Talbot said.
The Migration Act includes a provision stating that certain proceedings against the Commonwealth "may not be instituted or continued in any court" apart from the High Court.
But in its judgement, the High Court found this would not prevent lower courts from hearing the cases being appealed stating that it is "not a law that takes away the jurisdiction of those courts".
However, the High Court did rule the section could be used by the Commonwealth as an option for defence.
But it also appeared to discourage the action by stating that if "no practical benefit is to be gained by raising [the defence] ... the Commonwealth acting as a model litigant need not and, it may be expected, would not raise it".
The test cases before the High Court on Wednesday related to four children suing the federal government over poor medical treatment during their time in offshore detention on Nauru.
This included concerns over their access to appropriate mental health care with lawyers warning the conditions in offshore detention had posed an imminent threat to their life.
In a statement the Department of Home Affairs said it is considering the High Court’s reasons for the judgement.
“The Department is aware that there are other ongoing litigation matters that may be affected by the judgment,” the spokesperson said.
“It would not be appropriate to comment on any ongoing matters that are currently before the Court.”
