The Federal Government says a boat carrying four Sri Lankans was intercepted by border protection authorities off the Cocos Islands 10 days ago.
Immigration Minister Peter Dutton said the group was transferred to Sri Lankan authorities at sea.
In a statement, Mr Dutton said Australian authorities had interviewed those on board the vessel and decided they did not require Australia's protection.
He said the Australian and Sri Lankan governments worked together to disrupt the people smuggling venture
"The Coalition Government's policies and resolve are stopping illegal boat arrivals and are restoring integrity to Australia's borders and immigration program," he said.
"By working closely with our regional partners we save lives at sea and prevent vulnerable people being lied to and ripped off by people smugglers.
"Anyone attempting to enter Australia illegally by sea will never be resettled in this country." (ABC news)