Australia asked Indonesia to extradite an Egyptian people-smuggler suspected of being behind the deaths of more than 350 asylum seekers whose boat sank off the Indonesian coast last week, as allegations emerged that the refugees were forced aboard the leaky vessel at gunpoint.

At the same time, Canberra said it might take in some of the survivors of the disaster as a humanitarian gesture.

Yesterday, survivors of the shipwreck said they were taken in groups by small boats out to the heavily overloaded fishing vessel, anchored off the coast of Lampung, on the island of Sumatra.

They said when they saw it was sitting just half a metre above the water they refused to get on board, but were forced to do so by police armed with rifles.

One Middle Eastern refugee said he saw one of the men who had arranged the journey hit two refugees, while threatening others with a pistol.

A Jakarta-based representative of the United Nations High Commissioner for Refugees, Raymond Hall, said he had heard similar claims and that collusion by Indonesian security forces with people-smugglers had been reported in the past.

Meanwhile, Immigration Minister Philip Ruddock said the man believed to be behind the ill-fated journey, named by newspapers as Abu Quassey, should be extradited to Australia to face trial.

The man was reported to be a Jakarta-based Egyptian believed by Interpol and Australian intelligence agencies to have been involved in previous people-smuggling operations.

"We've passed [his name] on to Indonesia already on a number of occasions and he's one of the people we've sought," Mr Ruddock said yesterday.

There were just 44 survivors from the overloaded, 19-metre boat, which went down in the Sunda Strait, shortly after leaving the Indonesian coast. The death toll is believed to be 356.

Survivors, including women and children, spent up to 30 hours in the water, clinging on to wreckage and surrounded by slicks of oil and petrol.

The boat had set out with about 420 people, mostly Iraqi asylum seekers, bound for Australia's Indian Ocean territory of Christmas Island. It was believed to have been built to take no more than 150 passengers, and was overloaded with extra fuel.

On seeing the boat, 10 people refused to board. A small group was taken off the boat on an island near Sumatra.

Mr Ruddock said that while Australia would consider accepting some of the survivors as asylum seekers, any action would have to be weighed against the risk of encouraging more refugees to embark on similar journeys in the future.

"As tragic as this is, and I mourn for the people who've lost family, what they have sought to do is break our laws and come to Australia unlawfully, and if they are able to succeed in that, it becomes a green light for others to do the same thing," Mr Ruddock said.