Immigration Minister Scott Morrison has explicitly acknowledged that the Government is turning back asylum seeker boats, despite having a policy of not confirming or denying what takes place on water during Operation Sovereign Borders.

Mr Morrison says a report broadcast by the ABC's 7.30 program last night showing a turn-back involving an orange lifeboat shows that the Government's policy is working to stop the flow of asylum boats to Australia.

"It's now 89 days since there's been a successful people smuggling venture to Australia," Mr Morrison told Macquarie Radio.

"We turn boats back where it is safe to do so, and we are doing it in a way which ensures that it's safe.

"The policy has been enormously effective, it continues to be so, but we're not letting up and I think the program last night demonstrated, very clearly, that if people seek to get here the wrong way they won't get here."

The passengers spoken to by 7.30 are now in detention in Indonesia. They gave their accounts of being forced onto the lifeboat after being held on the Australian Customs ship Triton off Christmas Island for up to a week.

Iranian asylum seeker Arash Sedigh said it was the second time he had tried to reach Australia but been turned back.

He said that during their detention on board the Triton, he was separated from the other passengers so he could not warn them about their imminent return.

Mr Sedigh said he also had threatened to kill Customs officers after he had earlier requested medical attention for a pregnant woman and other sick passengers, a request he alleged was refused.

Mr Morrison says Mr Sedigh's threats will only reassure Australians who support the Government's tough stance.

"Australians watching that program last night will be very thankful that the Australian Government has a very strong policy on our borders to ensure that people don't get to illegally arrive in Australia with that sort of entitlement, expectation or demand," he said.

"I expect he wished he turned up under a Labor government, because if he'd turned up under a Labor government that boat then would have got to Australia."

UN refugee agency interviews asylum seekers

The United Nations refugee agency has conducted in-depth interviews with asylum seekers about what happened when they were turned back to Indonesia in an attempt to get details about Operation Sovereign Borders.

In January, the UN agency asked the Federal Government for information about boat turn-backs but it has told the ABC it is yet to receive an official response.

The Government says it has ongoing dialogue with the UNHCR on a range of matters.

Asylum seekers on the lifeboat towed back by Triton on February 5 began filming the journey, as they had done on their way towards Australia.

There were 36 asylum seekers, including a pregnant woman and a one-year-old child.

They say they had nearly made it to Christmas Island but were intercepted by an Australian border patrol and kept onboard the Triton for seven days.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 4 minutes 20 seconds 4 m 20 s UNHCR interviews asylum seekers over forced return to Indonesia ( George Roberts ) Download 2 MB

A contact on Christmas Island told ABC News that during that time two asylum seekers were transferred to the island for medical attention, wearing wristbands numbered 879.

Australian authorities used the same numbered wristbands to identify those seen in the lifeboat footage.

"The wrist bands show the boat number 879. It is a blue band with people's number," one of the asylum seekers said.

On the trip back to Indonesia, Iranian asylum seekers discussed two missing passengers.

One asked, "Ali and Hossain had a fight with them?", to which another replied, "They sent them back."

Just two days earlier, Mr Morrison told Macquarie radio there had been no boats for six weeks.

"We've had two persons transferred in the past couple of days for medical reasons, but no boat has got here," he said.

Mr Morrison was separately quoted as saying that one man had a heart condition, but gave no further details.

On reaching Indonesia, passengers from the lifeboat claimed there had been an altercation on the Triton.

A 48-year-old Pakistani man, who does not want to be identified after fleeing threats from Islamic militants, was on the boat.

He said: "One young guy, around, I think, looks like 28 years old, Iranian, and one old man. Then they told us they are… they bring them to the doctor. But we never see them again, these two people."

Other asylum seekers among the dozen spoken to by 7.30 gave similar stories, but it is impossible to prove or disprove without an official account of events on board the Triton.

Morrison plays down future ambitions

Mr Morrison's colleagues are privately praising him as one of the Government's stand-out performers in getting quick results on the controversial policy.

His future ambitions are being scrutinised following an interview he gave to his local paper where he confirmed he was open to new challenges.

Asked whether he will run for prime minister one day, Mr Morrison said he was up for "whatever challenge" but was focused on his current job.

"When people put that [leadership] question to me, I kindly sort of respond to them in a way which is 'look, thank you for that', but my job at the moment I think is pretty clear.

"There's a lot more work to be done here, and as I said in that interview, I'm up for whatever challenge there is but the challenge I have right now is very clear and that's the challenge I'm focused on."

Mr Morrison says he is confident "ability and performance" speak for themselves and they define future ambitions.

Know more? Email: investigations@abc.net.au