The High Court in Australia has stopped the deportation of a boatload of asylum seekers to Malaysia.
Lawyers for the group of refugees argued that their transfer to Malaysia would be illegal.
Judges ruled there was a ''sufficiently serious question'' and ordered a halt to such transfers until a full hearing can be held on 22 August.
The BBC reports the ruling could jeopardise a deal to send 800 asylum seekers to Malaysia over the next four years.
Under the deal, which was signed last month, Australia would take 4000 refugees who have already been processed in Malaysia.
But critics say refugees are often mistreated in Malaysia, which has not signed the UN Refugee Convention.
Those seeking the injunction were the first to be targeted under the agreement.
They were picked up in Australian waters and taken to Christmas Island, where hundreds of asylum seekers are kept in detention while their claims are processed.
High Court Justice Kenneth Hayne ruled there was a "sufficiently serious question" for the case to have a full hearing, ordering a temporary injunction on the transfers.
Australia currently has more than 6000 asylum seekers in detention originating from countries including Iran, Iraq, Vietnam, Sri Lanka and Afghanistan.
The UN has previously criticised Australia for holding all asylum seekers in detention centres while their applications are assessed.