China is on the march in the Pacific and it's moving well under the radar. Using strategies only open to a one-party state, the People's Republic of China (PRC) has a masterplan for our region that is both ominous in its scope and proving extraordinarily effective in its implementation.

When 60 Minutes embarked on a story about China's influence in the Pacific with reporter Liam Bartlett, we had no idea how conclusively we'd prove the case.

Our report would take in Kiribati and the Solomon Islands - the two Pacific nations to most recently switch their diplomatic recognition from Taiwan to communist China. Under its 'One China' policy, the PRC demands that countries within its diplomatic sphere cannot recognise Taiwan.

We would also visit Bougainville, the 'treasure island' of Papua New Guinea – soon to vote for independence. Likely to become the Pacific's newest nation, Bougainville would be a glittering prize for China.

In each place we'd discover a depth of PRC planning and influence that should rightly alarm the world and especially Australia.

The the site of one of the world's richest gold and copper mines, Bougainville is the 'treasure island' of Papua New Guinea. (60 Minutes)

Kiribati, the tiny atoll nation with the highest point on its main populated island Tarawa of only three meters, may look like a tropical paradise from the outside. But it's not. As we found, its recent diplomatic recognition of communist China has made a repressive media regime in the island nation even more draconian.

60 Minutes was told just days before our planned arrival on Kiribati that we would require a 'filming permit', which on close inspection was an extraordinary document – allowing the government to censor and seize our recordings and force us to rewrite anything not in line with the government's 'policies and priorities'.

No media organisation in the free world would agree to such terms, and we certainly weren't about to – but we decided we'd argue the toss on the ground. The Office of the Kiribati President, which enforces the conditions of the permit, agreed we could apply for it on arrival.

As revealed in the 60 Minutes report 'Seeing Red', our lack of a permit was the reason used by the Kiribati government to hold our crew under house arrest. But it turned out we also had friends in very high places, including Kiribati's first president and founding father Sir Ieremia Tabai GCMG AO. Along with Kiribati's Opposition Leader Titabu Tibane, Sir Ieremia visited us in the hotel where we were being held, to offer his support and deepest apologies on behalf of his country.

In an interview filmed secretly but with their permission, the two men described the lack of a free media in Kiribati and the virtual banning of foreign journalists like us, which they blamed partly on China's influence.

Kiribati's opposition leader Titabu Tibane and Kiribati's founding father and first president Sir Ieremia Tabai spoke secretly to 60 Minutes about the repression of free press on their island nation. (60 Minutes)

"This is the action of a communist country changing us around," Mr Tibane told Liam Bartlett. "This is a sad day for democracy."

Former Director of Intelligence for the US Pacific Fleet, Captain Jim Fanell was also part of our 60 Minutes team – helping us analyse the PRC's strategy in the region. His view of our detention in Kiribati?

"Could be that the Chinese have said [to the government] that part of this deal is you're going to have to pay more strict attention to who's here and what they're doing."

Sir Ieremia Tabai told Bartlett there'd been strong opposition by the Kiribati people to the recognition of the PRC. There had even been street protests, which had not been reported by the state-owned media. According to him, there had been a massive cash-splash by China directly after the country's diplomatic switch to the PRC to the tune of $250,000 – supposedly to support local sporting events but with little or no transparency as to how the money was distributed.

We'd been right to come without the notorious 'filming permit', he said, encouraging us to report without fear or favour on the real situation in Kiribati when we got out.

Interestingly, the Kiribati government under whose authority we'd been held under house arrest lost its majority a few days after we left. Opposition Leader Tibane told us by email he planned to move a no-confidence vote in parliament and conceivably form government himself. In that event, he said, Kiribati would almost certainly dump the PRC and re-recognise Taiwan.

The next stop on our Pacific tour of duty was the Solomon Islands, which also recently swapped its alliance to the PRC. As reported in 'Seeing Red', 60 Minutes uncovered claims of bribery by agents of China, trying to sway the Premier of the Solomons' largest island Malaita to turn pro-China.

Asked Liam Bartlett: "So they rang you and said, 'we've got $1 million for you if you come to the hotel and accept the switch to China'?"

"Yes," said Premier Daniel Suidani. "Maybe there are some of my colleagues who have been offered the same and they may have accepted it … but I didn't accept it."

The Solomons' charismatic deputy opposition leader, Peter Kenilorea, who spent two decades working at the United Nations in New York doesn't doubt that bribes have featured in his country's abrupt switch to the PRC.

"Do you think where there was one bag of money on offer, there's bound to be more?" asked Bartlett.

The Premier of the Solomons' largest island Malaita, Daniel Suidani, told 60 Minutes he was offered $1 million to switch his allegiance to China. (60 Minutes)

"Oh yes, they don't come in singles," said Kenilorea. "In terms of international diplomacy… it's a new way of doing things that is really dangerous."

60 Minutes also reported a shadowy attempt by companies linked to the PRC to take control of Tulagi Island, forty kilometres from the Solomons' capital Honiara, by way of a 75-year lease. We obtained a copy of the lease document, which was damning – a brazen attempt to usurp all rights on the island, including the deep-water port, oil and gas rights, fishing rights, forestry rights and tourism rights.

As the Solomons is a matrilineal culture, where land is owned by the women, the voice of Tulagi's people is the serene but determined Margaret Manu.

Deputy opposition leader of the Solomon Islands Peter Kenilorea is convinced that the Solomon Islands was bribed into changing its allegiance to China. (60 Minutes)

"Tulagi is very important to us, it's very important to us. It's a heart of the people," she told Bartlett.

"And, the people here didn't want to be owned by the Chinese?" he asked.

"No," said Margaret. "China is a communist country. And the Solomon Islands is a democratic country."

To Captain Jim Fanell, Tulagi lies in hallowed sea – the site of some of WWII's fiercest and deadliest naval battles between the Allies and Japan. Thousands of Allied sailors died and dozens of warships were lost – including Australia's HMAS Canberra. Little wonder the waters around Tulagi are known as 'Ironbottom Sound'.

As the intelligence chief of the US Pacific Fleet, Fanell gathered 24/7 intel on China's moves in the Pacific, but nothing quite prepared him for what he discovered on the ground with 60 Minutes.

"What we're seeing now from our visits to the islands here is that the Chinese are coming in with soft power and lots of cash to buy out local officials, to gain access to ports and airfields and resources that give them a controlling monopoly in the islands," he said speaking to Bartlett on Tulagi Island.

"And as time goes on it allows them to build up their own infrastructure, which then will firmly ensconce them in power in these places and thus give them control over this vital sea lane."

Central to the PRC's strategy in the Pacific is establishing what it calls a 'blue economic passage' through the Pacific Islands, all the way to the Antarctic. And it's when you superimpose that proposed sea-lane over the territorial waters of nations like Kiribati and the Solomon Islands that China's strategy becomes crystal clear.

According to Captain Fanell, the benign phraseology of 'blue economic passage' is, put bluntly, communist double-speak.

General Sam Kaouna and his wife Josie. (60 Minutes)

"It's the start of a comprehensive plan that they have to dominate the region. At first it's with economic development, but it will be followed by fishing fleets and maritime law enforcement and then eventually Naval forces."

As a post-script to our stay on the Solomon Islands – the day before our departure – the government announced an immense deal to sell the country's only gold mine to Chinese companies with PRC links. Seizing the moment to visit the Gold Ridge Mine – two hours' punishing drive into the mountains above Honiara – Bartlett and the 60 Minutes team were greeted at the gates by security guards in brand new uniforms with Chinese lettering and emblazoned with the PRC's red flag.

Liam Bartlett in front of the Gold Ridge mine in the Solomon Islands. (60 Minutes)

A mine insider told 60 Minutes that the uniforms had been ordered six months earlier, even though the Solomons' diplomatic recognition of the PRC, which opened the way to the mine sale, was only two months' prior.

But it would be on Bougainville – just a Pacific stone's throw to the north – where 60 Minutes broke major news. On the eve of a referendum for independence – long-coming since its bloody ten-year civil war with Papua New Guinea in which 10,000 people died – Bougainville is poised to become the Pacific's newest nation.

It is also the site of one of the world's richest gold and copper mines – the almost-legendary Panguna Mine, destroyed by war but still containing an estimated $60 billion worth of ore.

If it achieves independence, Bougainville would be a major diplomatic prize for China but there has seemingly been little concern in Australia and the US – and even less news – linking the PRC to any major plans for the island.

But all that changed when 60 Minutes encountered one of the rebel commanders of the Bougainville civil war, and now a leading contender to be president if it obtains independence – General Sam Kaouna.

General Kaouna was open with Liam Bartlett about his openness to the PRC – both in terms of diplomatic recognition and rebuilding the island's infrastructure.

"Today China is the superpower in the world," he said. "Bougainville is free to be choosing whichever countries that we can have the best deal with."

As our Pacific tour ended, we joined General Kaouna as he presented a comprehensive plan for the rebuilding of Bougainville to local government leaders.

It was a Chinese master plan. A banner-sized satellite image marked out future roads, ports and an airport. Beneath it detailed outlines of each infrastructure project, with Chinese characters spelling out the PRC's long-term ambition in Bougainville.

General Kaouna was adamant that his willingness to do business on such a huge scale with China was partly driven by what seemed a complete lack of interest in his nation-to-be by Australia and the US.

Compounding this was an inexplicable personal insult to him by Australian Foreign Affairs authorities, who denied him a visa to Australia. The General told Bartlett he had planned to meet with Andrew 'Twiggy' Forest, to discuss Fortescue Metals Group's potential interest in the Panguna Mine.

"I need an apology from whatever foreign affairs minister for stopping me to go down there," said Kaouna.

Captain Jim Fanell, former intelligence chief of the US Navys Pacific Fleet, has described China's soft invasion of the Pacific as deeply worrying. (60 Minutes)

"Australia is making an enemy out of Bougainville when they give me that treatment."

For veteran China-watcher and former US Navy intelligence director Captain Jim Fanell, General Koauna's revelations were deeply alarming and almost a final straw.

If Bougainville falls under China's sway, he told Bartlett, "it provides China with another Island in their island-hopping strategy.