It is understood the boat containing 29 Sri Lankans was detected near Cocos Island and was tracked towards mainland Australia before it was intercepted by Border Force officers on Wednesday.
Sri Lankan media reported the deportees — including two boys aged 12 and 15 — arrived back in the country on Thursday after being returned on a “special” flight from Learmonth Airport near Exmouth.
A spokeswoman for Immigration Minister Peter Dutton said they did not comment on operational matters.
The Weekend West understands the asylum seekers were brought to the mainland by ABF officers and flown back to Sri Lanka.
It is understood the boat the asylum seekers attempted to travel to Australian sunk and that they were returned by plane because authorities believed their vessel was not seaworthy and could not be safely turned back.
An Operation Sovereign Borders update, which covers the period of the incident, will not be released until next month.
But Prime Minister Malcolm Turnbull has boasted in recent weeks that an asylum seeker vessel had not made it to Australian shores in almost 31/2 years.
“We have restored John Howard’s strong policies and as you know there has not been a successful people-smuggling expedition to Australia in well over 1000 days,” he said.
“We know we don’t have to theorise about border protection policies.
“We know what works and we know what doesn’t.”