SARAH FERGUSON, PRESENTER: For six months, a shroud of secrecy has surrounded Operation Sovereign Borders, the strategy designed to stop asylum seeker boats reaching Australia.

There is little doubt it's working. Immigration Minister Scott Morrison told Parliament today it's been 88 days since the last successful people smuggling venture.

But exactly how the policy has been implemented remains a secret, with the Government refusing to provide details that it deems to be operational.

Now, a major investigation by the ABC has penetrated that veil of secrecy. Our journalists have gained rare access to passengers who describe the high drama as they were intercepted at sea, the scenes captured in confronting new footage taken onboard.

What you're about to see is one side of the story. We've been unable to verify some of the asylum seekers' claims about their treatment and we were refused permission to interview Australian personnel involved in the operation.

This is part one of a two-part special by Indonesia correspondent George Roberts and producer Mark Solomons. It contains strong language.

GEORGE ROBERTS, REPORTER: In the treacherous seas off Australia's north-west, an intensely secretive operation is underway. An Australian Customs patrol ship tows an enclosed orange lifeboat towards Indonesia. Inside, there are 34 asylum seekers from Iran, Pakistan, Bangladesh and Nepal and two Indonesian crew.

It's a pivotal moment in Australia's border protection campaign and the first filmed evidence of a tow-back.

Tonight, a unique insight into Operation Sovereign Borders, the Government's controversial strategy to stop the boats.

ARASH SEDIGH: I ask them, "If we will die in these orange boats? It's not suitable for passing the ocean." They told me, "That's not our problem. That's yours. If you die in the Indonesian water, Indonesian Government in trouble and responsible. That's not our problem."

GEORGE ROBERTS: This story begins a week earlier at Cisarua in the hills south of Jakarta in West Java. Thousands of asylum seekers come here hoping to board boats to Australia.

Iranian Arash Sedigh and his wife Azi were among them.

ARASH SEDIGH: I have problem in Iran. There is no human rights and freedom. The Iranian Government made problem for my family several times and I decided to change my religion. And in Iran it's so dangerous, as you know, as everybody knows.

GEORGE ROBERTS: After Arash Sedigh was refused entry to Australia through the skilled migration program, they came to Indonesia to apply for resettlement as refugees, but gave up waiting and turned to people smugglers.

ARASH SEDIGH: We decided to go there in illegal way, to make them accept us.

GEORGE ROBERTS: On 27th January they set off in a small wooden boat with 34 others. One of the passengers filmed the journey on a mobile phone. The waters were calm and their spirits high as they travelled south towards Christmas Island.

This was Arash Sedigh's second attempt to reach Australia by boat and he was determined to make it this time.

ARASH SEDIGH: I promised my wife, Azi, "I will take you to a safe country and safe place to stay." There is many job opportunities for me in Australia. I'm pretty sure that then I can work, I can earn money and I can make a wonderful life for my family.

GEORGE ROBERTS: It was smooth sailing for two days, but as they neared Christmas Island, the wooden fishing boat began to take on water. That's when this Iranian Nuradin (phonetic spelling) Mousavi spotted an Australian border patrol.

NURADIN MOUSAVI: They dropped two boats from the Navy ship, they sailed towards us. When they arrived, they started without saying anything. We asked for help. "Our boat has holes, we are sinking." They only kept saying to us, "Shut up, don't move and sit down!"

ARASH SEDIGH: When Customs come inside our wooden boat, I just ask them, "Please, please help us. Would you please take us in a safe place?" They just shouted on me, "Shut up, shut up, sit down!"

GEORGE ROBERTS: Arash Sedigh became angry after demanding a doctor to treat sick passengers and a pregnant woman.

ARASH SEDIGH: I stood up. I shouted on them, "You have to help us! I know you have to help us! You cannot deny you have got doctor in that Customs ship!" The Customs crew told me, "No, there is no doctor, we have no doctor." I told them, "I know that there is doctor in your ship." He told me, "No, no." I couldn't tolerate. I told them, "I will kill you if you don't take us to that ship. I have nothing to lose. I will kill you. Believe me. For Jesus Christ, please help us. Would you please help us?"

GEORGE ROBERTS: As their boat foundered, the asylum seekers were taken onboard the Australian Customs ship the Triton.

NURADIN MOUSAVI: From there, they shift us in front of the boat, have their basement totally locked. They put everybody inside.

MAHBOUBE MOUSAVI (subtitle translation): They put us in a very dark room. No matter how much we begged them to put a light bulb in the room, they would just shut the door on us, although there was a very small window. They covered it with cardboard from the back so that we wouldn't see any light.

GEORGE ROBERTS: Nouradin (phonetic spelling) Mousavi and Mahboube say they were kept onboard the Triton for almost a week.

MAHBOUBE MOUSAVI (subtitle translation): My heart troubled me there very much. I actually saw death in from of my eyes. I had difficulty breathing. I asked them to at least remove the cardboard and open the door so that we have fresh air. They said, "We are not allowed."

ARASH SEDIGH: They pushed us, they punched us, when we were just asking for our rights. They just told us, "Shut down, shut down - sit down, shut up. Sit down, shut up." And ...

GEORGE ROBERTS: Is that because asylum seekers were protesting or being violent?

ARASH SEDIGH: Yeah, sometimes protesting, sometimes asking for some rights, you know, some facilities. Like, as I told you before, for example, contacting their families.

GEORGE ROBERTS: Back in Canberra, the Government was firm in its resolve to maintain secrecy over Operation Sovereign Borders.

SCOTT MORRISON, IMM. & BORDER PROTECTION MINISTER (Jan. 31): This operation is working, Chair. The boats are stopping. The way we manage information is an important part of this operation.

GEORGE ROBERTS: Australian Customs had deployed a new weapon in the campaign: a fleet of high-tech orange lifeboats.

ANGUS CAMPBELL, COMM., OPERATION SOVEREIGN BORDERS (Jan. 15): I can confirm that the Australian Customs and Border Protection Service has purchased a number of large lifeboats. These lifeboats are an additional element in that wide range of measures I've spoken of, designed to achieve the aims of Operation Sovereign Borders. ... While confirming the acquisition, I'm not going to provide information regarding the potential or actual employment of these lifeboats, now or in the future.

GEORGE ROBERTS: But even though Angus Campbell wouldn't reveal any details, there were soon reports that orange lifeboats were being used to send back asylum seekers.

NEWSREADER (ABC News, Feb. 1): Pictures have emerged of a lifeboat used to transport asylum seekers back to Indonesia as part of the Government's Operation Sovereign Borders. The boats are used when ...

GEORGE ROBERTS: The first evidence was these pictures o a lifeboat that washed up on the Indonesian coast in mid-January.

Arash and Azi Sedigh had been sent back on that orange lifeboat after their first failed attempt to reach Australia.

ARASH SEDIGH: Everybody were vomiting, just baby and women crying, screaming, everybody vomiting, sick.

GEORGE ROBERTS: Now, several weeks later, onboard the Customs ship the Triton, Arash and Azi Sedigh dreaded being forced on an orange lifeboat again.

ARASH SEDIGH: Several times I asked them, "Please, please, would you please, could you please ask Australian Government, if you want to turn us back, to return us back to Indonesia? Please give us to Indonesian Navy or Indonesian police. No problem for us. Please don't send us by that orange boat. We have bad memories, believe us, we have very bad memories."

GEORGE ROBERTS: But those fears were soon realised.

MAHBOUBE MOUSAVI (subtitle translation): Very early in the morning while we were asleep, so were the kids, they woke us up very harshly. They constrained us with force, they did not even allow us to take out personal belongings, nothing.

AZI SEDIGH (voiceover translation): When I saw the orange boat, I understood that all of that will be repeated again. ... I was just screaming. I kept saying, "This boat of yours is not suitable for me to board again." With my hands, I was holding on to the side of the boat that they took us to. I was just screaming, but the only thing they did was to pull me forcefully towards the boat.

ARASH SEDIGH: They just told me, "Shut up, shut up," just always. And they fight with me, they punched me, and suddenly, pushed me in the ocean.

AZI SEDIGH (voiceover translation): I only saw that Arash was in the water. When he returned to the boat, it was there that he told me, "They pushed me into the water themselves."

ARASH SEDIGH: After that, they took me from the water, they pushed me into the orange boat. After that, I just asked my friends, "Does anybody have a camera? We have to take movie as evidence."

GEORGE ROBERTS: The asylum seekers filmed the next part of their voyage on a mobile phone.

On the morning of 5th February, the Triton towed the orange lifeboat towards Indonesia.

NURADIN MOUSAVI: Boat was very strange smelly and very small as people reaching there so we felt vomiting, vomiting, vomiting, vomiting.

GEORGE ROBERTS: As they got closer to Indonesia, the Australians cut them loose.

Some of the men climbed onto the roof as the Indonesian crew steered them towards Java.

Arash Sedigh provided a running commentary on the journey.

ARASH SEDIGH (on asylum seeker boat): They put us in this f**king orange boat and sent us back to Indonesia. And the Navy was escorting that ship until today. ... F**k Australia. ... I said to them, "You are criminals". If later on you said why they do that to America on September 11, you should know the cause of it is your very deeds. Remember 9-11 for United States. All the world should know why. Australian Government, Tony Abbott, Scott Morrison, Immigration - all of them are the smugglers.

MAN (on asylum seeker boat): F**k Australia!

GEORGE ROBERTS: Late on 5th February, nine days after they set off, their bid to reach Australia ended at this fishing village in West Java.

YATIN KAMAL: I saw the boat land here and then after - I saw, I mean, the immigrant people, they jump. We had two couple, the people, they came to the bar and talk with our friend and they came to our office, "Come out, help the UFO."

GEORGE ROBERTS: UFO?

YATIN KAMAL: Yeah, UFO. "Come to beach." "Where, where, where?"

GEORGE ROBERTS: Indonesian police secured and impounded the orange lifeboat. The asylum seekers were taken into custody and transported to a makeshift detention centre.

A few days later, 7.30 found the orange lifeboat at its mooring in Pangandaran.

After some negotiation, Indonesian police granted us permission to board.

Well there's not much room to move in here, and even on a day like today, where there's no swell, the boat is rocking around a little bit. It's also boiling hot in here. One of the Navy guys who spent five minutes inside described it like a sauna, so it's easy to see why the asylum seekers off this boat found the trip so uncomfortable, and in some words, traumatic, that they don't want to take a boat again.

Now in detention, four-year-old Ashkan plays with lifejacket beacons from the boat which brought him and his family back to Indonesia.

MAHBOUBE MOUSAVI (subtitle translation): I don't think I will ever forget this ordeal to the last day of my life.

GEORGE ROBERTS: Even after two failed attempts to reach Australia, Arash Sedigh says people smugglers are encouraging him and his wife to try again.

ARASH SEDIGH: They just told me, "You can go. We will send you several times. But you cannot get back your money."

GEORGE ROBERTS: So will you try to go again?

ARASH SEDIGH: Me? No. I have two times bad experience about this trip. I don't want to make my wife in trouble again. I want her for living together. I don't want to make her die.

SARAH FERGUSON: Indonesia correspondent George Roberts and producer Mark Solomons with that report, which was edited by Pru Kingsmill; post-production by Lesley Robinson.

7.30 submitted a list of 28 questions to the Government and Border Protection agencies. They declined to provide answers.

A spokesman for the Immigration Minister gave 7.30 a short statement. It says there are clear rules to cover the use of force to ensure operations are conducted safely and the Government rejects unsubstantiated allegations of inappropriate conduct.

We'll bring you part two of our investigation later this week.