Ten asylum seekers have launched a High Court challenge on the legality of the Australian government's offshore detention policies, in a bid to prevent their return to Nauru.
The asylum seekers and their families, including a newborn baby, have been temporarily moved to Australia for medical treatment, but are facing imminent return to offshore detention.
The Human Rights Law Centre in Australia is running the case on behalf of the asylum seekers.
Its director of legal advocacy, Daniel Webb, says the group is asking the court to rule on whether the government has the power to detain asylum seekers in foreign countries, and spend taxpayer money for that purpose.
"The matters that are raised in this case go right to the heart of the current offshore detention arrangements. They challenge whether the government has the power to procure detention offshore and whether the government has the power to spend money for that purpose."
The Human Rights Law Centre's director of legal advocacy, Daniel Webb.