One Sri Lankan national on a boat of 38 asylum seekers turned back by Australian authorities on the high seas has been transferred to an offshore processing centre.
The boat was intercepted by Australia's coastguard northwest of the Cocos (Keeling) Islands on November 15.
At no time was the trawler in distress, and all on board were safe and accounted for.
The Australian and Sri Lankan governments worked together to disrupt the people-smuggling venture, a statement from Immigration Minister Scott Morrison said on Saturday.
Everyone on board was individually assessed by trained protection officers who determined that in one case, a referral for a refugee determination process was recommended.
That individual will be transferred to Papua New Guinea or Nauru for processing, the statement said.
The remaining 37 were transferred at sea to Sri Lankan authorities on Wednesday evening and have since been arrested.
"The boat left Sri Lanka on November 1," Superintendent Ajith Rohana said in Sri Lanka, adding that six children were among the passengers.
"Investigations are being conducted by the anti-people smuggling unit of the CID (Criminal Investigation Department).
"They are being held in custody, but will be taken before a magistrate shortly."
The Tamil Refugee Council has criticised the Australian government's decision to return the asylum seekers, saying it has "almost certainly condemned (them) to persecution, including torture, by returning them to their homeland".
The screening system used by authorities is an illegal and insufficient test, the council said.
"The idea that you can properly test a person's claim for refugee status at sea has been condemned by well-respected legal and human rights groups many times, yet this government cares nothing for its legal, moral or ethical obligations," the council's Trevor Grant said in a statement.
The returns were the first since July when a boat loaded with 41 nationals was intercepted by Australia.
Sri Lanka charged them with illegally leaving the country, and their cases are due to be taken up by a court next May.
Australia has gifted two vessels to Sri Lanka's navy to patrol its shores and stop boats leaving the island, as part of Canberra's hardline border protection policy.
