CHRIS UHLMANN, PRESENTER: The Queensland Government bell Newman's election campaign. Two years ago sand miner Sibelco helped propel Mr Newman into Parliament. Now 7.30 has obtained documents that show the Newman Government is proposing to extend the life of a lucrative sand mine run by the company which had been earmarked for closure. The news has angered the local native title holders, who claim the deal was done in secret. From North Stradbroke Island, Peter McCutcheon reports.

PETER MCCUTCHEON, REPORTER: The Quandamooka people are celebrating the second anniversary of gaining native title to their island home off the south-east coast of Queensland. It's the beginning of what many here hope will be a new era.

???: I feel really emotional because our ancestors, my parents, you know, they never really would have known that this was possible.

PETER MCCUTCHEON: But celebrations are tempered by a feeling these long-fought-for rights are being undermined by the Newman Government.

DARREN BURNS, QUANDAMOOKA YOOLOOBURRABEE ABORIGINAL CORP.: They just push us to the side of the road like Aboriginal people have been for a long time now, just pushed to the side of the road, out of the way so they can go ahead and get what they want.

PETER MCCUTCHEON: The Quandamooka live on North Stradbroke Island, renowned for its beaches, world-famous wetlands and over 60 years of sand mining. It's a lucrative resource on Aboriginal land and the Quandamooka are fighting for the right to have a say over the mine's future.

CAMERON COSTELLO, QUANDAMOOKA YOOLOOBURRABEE ABORIGINAL CORP.: We've attempted to meet with the Premier in good faith. We've met with the Mining Minister in honest, upfront good faith. That's always we've done that. And it just appears that that's not being reciprocated.

PETER MCCUTCHEON: Belgian company Sibelco presently operates three mines on the island, exporting tens of thousands of tonnes a year of rutile and other minerals to more than 30 countries around the world. But after 60 years of dredging, the mines are coming to the end of their life.

Two years ago, the Bligh Labor Government announced the largest mine, Enterprise, would finish production by 2019, eight years earlier than the company was planning for.

And the Bligh Government passed special legislation, giving the Quandamooka joint management rights over a new national park as part of a move towards nature-based tourism.

???: The land to us, the waters that we have behind us, it's our very lifeblood.

PETER MCCUTCHEON: Sibelco, its 280 employees and supporters on the island were furious about the early closure of the Enterprise mine.

WOMAN (Sibelco advertisement): Sand mining has been a godsend to us on the island.

PETER MCCUTCHEON: The company directly responded with a multimedia marketing blitz it called "Straddie Stories". It had the desired effect. Early in last year's state election campaign, the LNP leader Campbell Newman declared his opposition the 2019 closure date.

CAMPBELL NEWMAN, LNP LEADER (Jan. 2012): We will allow the mine to proceed in the way that it was originally allowed to prior to the actions of the last 18 months.

PETER MCCUTCHEON: The mining company followed this up by directly assisting Campbell Newman in what was expected to be a tough fight to win the safe Labor seat of Ashgrove in Western Brisbane. The miner was caught out posting letters to votes from mine supporters without required disclosure urging a vote for Campbell Newman.

Sibelco belatedly obtained authorisation and last year filed a disclosure revealing it had spent more than $90,000 on postage and printing.

On gaining office, the Newman Government discovered its promise to extend sand mining could potentially conflict with native title rights, and unbeknownst to the Quandamooka, LNP ministers and Sibelco have been closely working together for the past 14 months to find a way around this legal obstacle.

7.30 has obtained a ministerial briefing paper by Sibelco on how to frame new legislation and a pre-cabinet government circular seeking permission to put this proposal into practice. The documents say mining at Enterprise will extend through to 2035, eight years longer than had been previously announced.

By continuing it to 2035, aren't you going beyond the Premier's election commitment?

ANDREW CRIPPS, QLD MINES MINISTER: Well, we asked them to go away and come up with a package that would provide for a much smoother transition process.

PETER MCCUTCHEON: The documents reveal a plan to lift restrictions on the path of the Enterprise mine that were put in place by the Bligh Government to protect areas of high conservation value. Sibelco has declined to be interviewed on camera, but the company told 7.30 these restrictions were unnecessary as they didn't provide the best environmental outcome. The Government circular also acknowledges the proposed legislation could be vulnerable to a legal challenge by the Quandamooka Yoolooburrabee Aboriginal Corporation, or QYAC.

(male voiceover): "Crown law advise that if the legislation was challenged by QYAC there may be a risk ... the legislation extending the leases could be found invalid."

PETER MCCUTCHEON: Is the Government going out on a legal limb here?

ANDREW CRIPPS: Well, our advice is that that's not the case. Of course, if the briefing notes are saying that Crown law advice says that there's a risk, then that's the alternative view.

PETER MCCUTCHEON: In contrast to detailed negotiations between the Queensland Government and Sibelco over the past 14 months, the Quandamookas say they've only had one meeting with Minister Cripps in which he failed to disclose the Government's legislative plans.

CAMERON COSTELLO: The relationship between Sibelco and the Premier and Sibelco funding him in his electorate in Ashgrove, which is no secret, it's - I think that's muddied the judgment of the Government.

PETER MCCUTCHEON: But the Minister argues the Government has always been upfront about its intentions to extend mining as part of an election promise.

What the Quandamooka argue is you've gone about implementing that promise by talking almost exclusively to the mining company and ignoring the owners of the land.

ANDREW CRIPPS: Well, as I've already outlined, it was very difficult to commence negotiations with the Quandamooka people when they indicated that they didn't want to undertake negotiations when the proposals involved an extension of sand mining activities.

PETER MCCUTCHEON: If the Government pushes ahead with this legislation, what have the Quandamooka lost?

CAMERON COSTELLO: Well basically, we're gonna be offered the scraps, you know, so - or nothing. So what's the mining company got to deal with us if it's been legislated? They don't have to deal with us and we're just seeing history repeat itself.

CHRIS UHLMANN: Peter McCutcheon reporting.