REFUGEE

A DESPERATE search was under way last night for at least 15 Sri Lankan asylum seekers missing in the Indian Ocean after their boat sank in darkness as it headed towards Australia.

Search aircraft and ships were combing an area about 330 nautical miles north-west of the Cocos Islands, where the vessel sank.

An Australia-bound LNG tanker and a Taiwanese fishing boat had picked up 19 people by yesterday.

A Royal Australian Air Force P-3 Orion also dropped a life raft yesterday afternoon for two asylum seekers seen bobbing in the water, while another three were seen clinging to debris. They had been in the water for more than 14 hours.

The captain of the tanker that rescued 17 of the asylum seekers said when his ship arrived on the scene on Sunday night the boat had already sunk.

"There were people everywhere around with some oil spill," said Nikola Brzica, the Croatian captain of the LNG Pioneer.

"They were in the water and about 10 to 20 minutes later it got dark, I was not able to see any more. I plotted the position where the refugee vessel sank.

"Some of them (were rescued) when we heard the crying and big noise from sea. Some of them came over gangway, some of them from the poop deck, some of them were in a life raft which is still floating there."

He said the plan was to take the survivors to Christmas Island once the search and rescue operation was called off.

Confirmation that the boat was carrying Tamil asylum seekers adds to the political pressure on Prime Minister Kevin Rudd over the issue.

Another 78 Tamils have now spent more than a fortnight on board the Australian customs vessel Oceanic Viking, which remains stranded off Indonesia as the asylum seekers refuse to disembark and demand to be taken to Australia.

Mr Rudd said yesterday he had spoken by phone to Sri Lankan President Mahinda Rajapaksa about the flow of refugees from that country's ''extraordinary'' civil war.

Mr Rudd also said last night that he was sending one of Australia's most experienced diplomats, John McCarthy, who has just returned as high commissioner to India, as special envoy to Sri Lanka to deal with the growing refugee problem.

There were initially believed to be 39 people on board the latest refugee boat but a Tamil representative in Australia said last night he had been told there were 42 men, women and children aboard including the crew.

While Government ministers were refusing to say all day whether those on the boat were asylum seekers or not, Tamil community leader Wicki Wickiramasingham told The Age the people were definitely Sri Lankan Tamils.

''They wanted to save their lives, they came straight from Sri Lanka,'' said Mr Wickiramasingham, from the group Justice and Freedom for Ceylon Tamils.

Mr Wickiramasingham said he had received calls from Colombo from families and friends worried about the safety of those on the boat, which left Sri Lanka more than three weeks ago. ''The people are phoning me from Canada, from London, from Colombo,'' he said.

The Australian Maritime Search and Rescue Authority received the first distress call at 7.10am (AEST) on Sunday, a spokeswoman for Customs and Border Protection said. The call was made directly from people on board.

By 11.02 am, the authorities broadcast a distress alert to all ships within 12 hours of the vessel in Australia's search and rescue zone.

A spokesman for Home Affairs Minister Brendan O'Connor said the trawler got to the vessel at about 4pm on Sunday. The vessel appeared to be taking on water but the pumps were coping and it did not seem to be in danger of sinking then.