Asylum seekers held in onshore detention have been given the green light to continue a legal fight to keep their mobile phones.
Immigration officials intended to seize all detainee phones and SIM cards on February 19, but were stymied by a class action launched by human rights lawyers.
The government questioned whether the Federal Court could hear the case, but their challenge was dismissed on Friday and the matter given the go-ahead.
National Justice Project solicitor George Newhouse described the outcome as "a small but important victory".
"But it's a long journey ahead and we're up against a government that will oppose human rights at every turn," he said.
"The blanket ban on phones punishes innocent men, women and children and demonstrates the increasing criminalisation by this government of asylum seekers who have committed no crime."
Immigration bosses last month told a Senate inquiry they could not manage a safe and secure environment for inmates of onshore detention with mobile phones present.
The devices were not just contraband and currency, but could be used to organise escapes, bring illegal items including drugs into facilities, and maintain criminal enterprises within detention centres.
The use of mobile phones for "nefarious" activities was widespread across the detention network, senators were told.
Some 179 phones had been "returned" by detainees as at the end of February.
Australian Border Force head Roman Quaedvlieg said at the time he would like people to have access to legal advice and to contact their families in the privacy of their rooms, as opposed to public phones.
But he could not reconcile this with his concern for running secure centres for his 1400 detainees.
Friday's court ruling stops guards from implementing a blanket mobile phone ban until the case is over, but they may continue to seize phones on a case-by-case basis, it is understood.
The ruling does not affect those whose mobiles have already been surrendered, but they may launch legal action to retrieve their phones further down the track if this court case succeeds.
The immigration department has been contacted for comment.
