Prime Minister Tony Abbott says he "deeply" regrets that an asylum seeker was given limited access to her sick baby, but won't apologise "for what happens when people come to Australia illegally".

Latifa, a Rohingyan woman from Myanmar, gave birth in Brisbane's Mater Hospital last week but was returned to a detention centre while her baby remained in the neonatal intensive care unit.

For several days the Immigration Department only allowed Latifa to visit her baby at the hospital between 10:00am and 4:00pm.

Mr Abbott says he has read reports about Latifa's case and "deeply" regrets that she was separated from her child.

"But we've got to ask ourselves, why have any of these things happened?" he said on the sidelines of the Commonwealth Heads of Government Meeting in Sri Lanka.

"They've happened because people have come to Australia illegally by boat and if you want to avoid these things, you've got to stop the boats.

"I don't, as it were, apologise for what happens when people come to Australia illegally by boat, because I am determined, as the new Government is determined, to stop this dangerous, this horrible business."

The baby was discharged from hospital on Thursday.

A spokesman for the Immigration Minister Scott Morrison said on Thursday that doctors at the hospital had advised it is common for mothers not to stay overnight because of bed restrictions.

Latifa was only allowed to visit her baby between the hours of 10:00am and 4:00pm. ( Supplied )

But in a statement, the Mater Hospital suggested Latifa should have been allowed to visit her child whenever she wanted.

The hospital says it encourages new mothers to be involved in the baby's care wherever possible to help establish a strong bond, and does not place restrictions on visiting hours.

"Mater places no restrictions on women and they can visit their baby anytime where possible," the statement said.

In his weekly media briefing on Friday, Mr Morrison revealed he has asked his department to investigate the matter.

"I have requested my department to look at the arrangements that were put around that particular instance to ensure that a mother would have as much access to their child as they would request and consistent with the standards and opportunities that would be otherwise available to any Australian at that hospital," he said.

"The issue here was also bed restrictions and bed restrictions don't apply only to people who might be transferees in this situation, they apply to Australians as well."

"I'm sure no-one is suggesting that anyone who found themselves in this situation as an asylum seeker should be receiving preferable treatment over, to any, Australian in that situation."

Former Liberal leader John Hewson this morning accused Mr Morrison of arrogance and condemned the decision to limit the woman's access to her baby as inhumane.

"It's inhumanity in the extreme in my view, I mean a mother in these circumstances is normally given 24-hour access to a child in intensive care," Dr Hewson told Sky News.

"I mean for heaven's sake, Morrison can go make all the short-term points he likes out there, but this is something I think that sends absolutely the wrong message."

Government to split border protection briefings for 'integrity'

Meanwhile, the Federal Government is changing the way it involves the military head of its border protection operation in its weekly media conferences, saying it wants to protect the integrity of the Australian Defence Force.

Mr Morrison says Operation Sovereign Borders Commander General Angus Campbell will no longer be present for the entire weekly briefing.

From now, Mr Morrison says, General Campbell will give his weekly report on the number of boat arrivals and take a few questions before leaving.

The move comes in the wake of criticism of the Government's tight control of information about the operation.

At last week's briefing, General Campbell repeatedly refused to give details about questions he said related to "on-water matters".

This week, he said three asylum seeker boats had arrived in the reporting period, carrying a total of 163 asylum seekers and eight crew.

Two boats arrived at Christmas Island, one on Sunday and one on Monday. Another boat arrived in Darwin on Monday.