Up to 12 asylum-seekers are believed to have drowned during a failed attempt to reach Australia from Indonesia, including at least two Sri Lankans from the Merak boat intercepted last year at Prime Minister Kevin Rudd's request.
The Afghans and Sri Lankans who died last week are understood to have been trying to transfer from a small fishing boat to a larger Australia-bound vessel in stormy weather at night when their craft capsized, The Australian newspaper says.
Only two asylum-seekers and one crewman escaped, according to fellow refugees who have been in contact with the survivors.
Indonesian authorities say they have no record of the incident, which the survivors have said took place last Monday.
The two survivors, as well as two of the dead, were from the Jaya Lestari, the 30-metre wooden cargo boat bound for Australia that Indonesia seized off western Java last October as a favour to the prime minister in order to send a message to people-smugglers.
Dozens of the original 254 people on board the Jaya Lestari escaped early this year. The remaining 122 were eventually transported to the Australian-built detention centre at Tanjung Pinang, on Bintan island.
Some of the escapees reached Christmas Island several weeks ago. Many are believed to have been hiding from Indonesian authorities in Jakarta and elsewhere, awaiting their chance to make the trip to Australia.
A spokeswoman for Home Affairs Minister Brendan O'Connor said a maritime incident in Indonesian waters would have to be confirmed with Indonesian authorities.