Sri Lanka's police have arrested 37 nationals turned back by Australian authorities on the high seas after attempting to seek asylum in the first such case in four months.

Another passenger on the boat, intercepted by Australia's coastguard north-west of the Cocos Islands on November 15, was found to have a case for claiming asylum and was being sent to Papua New Guinea or Nauru for processing.

Sri Lankan asylum seekers sent back by Australia in July enter court in Galle, Sri Lanka. Credit:AFP

Sri Lankan Superintendent Ajith Rohana said the coastguard handed the asylum seekers, including six children, over to Sri Lanka's navy on Thursday.