She said the claim was based on information from a ''very reliable'' source and was the key motivation for her bid to visit the centre on Wednesday.

Immigration Minister Scott Morrison has conceded that none of the asylum seekers may agree to meet Indian consular officials, but warned that this would mean being sent to indefinite detention on offshore processing centres on Nauru or Manus Island.

''It could be possible that all of them may choose not to speak to Indian consular officials, and in so doing they will pass up an opportunity to potentially be reunited with their families in India,'' he told the ABC’s 7.30.

While the 157 are all believed to be from Sri Lanka, Mr Morrison claimed the vast majority had been living in India for a ''very long time''.

''If advocates are telling them they should not talk to Indian consular officials, then I question whether they’re acting in their best interests,'' he said.

Implying that life as a refugee in India would be preferable to being sent to Nauru or Manus, he said the asylum seekers sent for offshore processing would never be resettled in Australia and would probably never be able to return to India.

The Australian Human Rights Commission will hold its third public hearing on Thursday into the children in detention centres, where medical experts who have visited the offshore processing centres will be compelled to give evidence.

This will be the first time a number of senior immigration bureaucrats have faced the inquiry, including Immigration Secretary Martin Bowles and Deputy Secretary Mark Cormack.

On Wednesday, Alan Tudge, the Parliamentary Secretary to the Prime Minister, said children being held in detention were not in danger.