A group of African athletes who went missing during the Commonwealth Games must give themselves up when their visas expire, although it appears some have already been granted bridging papers.
Home Affairs Minister Peter Dutton says the athletes must come forward and warns they can be deported if they overstay the visas granted to attend last month's Gold Coast games.
The 11 athletes will be in Australia illegally from midnight on Tuesday unless they've taken legal steps to stay remain.
But the chairman of Sydney's Northern Beaches Refugee Sanctuary, David Addington, says some of the 11 have already been granted bridging visas.
While he's not personally involved in their cases, he says he's spoken to advocates who are.
"I know that some of them have already been given bridging visas ... so you don't get detained," Mr Addington told AAP.
"A number of them have already lodged applications."
Sydney's Refugee Advice and Casework Service told The Daily Telegraph some of the 11 had sought legal help.
Mr Dutton said the athletes must present themselves to Australian Border Force officers and authorities would deal with their claims in due course.
"But if people have breached their visa conditions ... enforcement action will take place to identify those people and to deport them if they don't self-declare," the minister said in Melbourne.
The missing athletes include five boxers and three wrestlers from Cameroon, two athletes from Uganda and a Rwandan para-powerlifting coach.
There are also concerns about two Sierra Leone squash players who missed events, although their nation has insisted neither is missing.
Mr Addington helped 14 athletes from Sierra Leone get protection visas after the Melbourne 2006 Commonwealth Games.
All are now Australian citizens.
But he says the 11 Gold Coast athletes might not find it so easy to remain in Australia permanently.
"In 2006, Sierra Leone was a country Australia was accepting refugees from and at the moment we're not," he said.
"You've got to prove you've got legitimate fears for your life based on your own political, religious, tribal agenda or sexuality."