After being contacted by a refugee advocate, Fairfax Media spoke via satellite phone to two of the 153 people allegedly on board the boat.

A female Tamil passenger said it was carrying 37 children and 32 women.

''We need some help,'' she said. ''We are refugees.'' The woman said they did not pay any money to board the boat, which she said left from Puducherry in the south of India on June 13.

Another man came to the phone saying, ''We have come to Christmas Island because we don't have anything. We have travelled all the way from India.

''The boat is damaged, it is leaking,'' he said. ''There are children, including infants, and we are unable to manage.''

Asylum seekers on board the boat say they were given rice and fish by Indonesian fishing boats.

No vessel carrying asylum seekers has successfully reached Australian shores since December 19.

However, this boat is likely to be a major challenge to the government's turn-back policy, given it has not departed from Indonesia.

In March, the Abbott government tripled the money spent on the large orange lifeboats used to tow back asylum seekers breaching Australian waters to Indonesia to $7.5 million as part of its tough border control policy. It is unlikely the government could return the boat to India in one of these lifeboats, given their short-trip purpose.

Fairfax Media has informed the Australian Maritime Safety Authority of the details of the boat.

Immigration Minister Scott Morrison would not comment on the vessel, nor its position, but said there had been ''no significant events involving extreme risk of safety of life at sea''.

A spokesman said: ''For operational security reasons, the government does not confirm or otherwise comment on reports of on-water activities in relation to Operation Sovereign Borders or disclose details of any operations other than where there have been significant events involving extreme risk of safety of life at sea.''