Local resident Jack O'Donnell said he spotted an overcrowded boat just after 8:00 am local time, about 200 metres offshore, ABC news reported.
He said the four men onboard then swam ashore.
"About 10 minutes later four of the refugees, they're Tamils, swam with life jackets through the surf," O'Donnell said.
He added that one asylum seeker spoke broken English and told him there were 69 people on board, including women and children. O'Donnell said he alerted the local police who attended and spoke to the four men.
A spokeswoman for Customs said that the department had no information about the arrival but it is understood the boat has been towed to the island's lagoon.
Melbourne: A boat carrying 69 asylum seekers reportedly arrived undetected at the Cocos Islands off the western coast of Australia on Wednesday.
First Published: Wednesday, August 01, 2012, 15:01