Queensland’s Labor opposition wants the Crime and Misconduct Commission to see if a sand mining extension is linked to an LNP donation.

The Queensland corruption watchdog has been asked to investigate if a donation to the state’s Liberal National Party led to an extension of sand mining on North Stradbroke Island.

The previous Labor government had legislated to end all sand mining by 2025, but last year the LNP government extended Sibelco’s lease for its main Enterprise mine from 2019 to 2035.

Sibelco spent $90,000 helping Campbell Newman win the Brisbane seat of Ashgrove off Labor to become premier in 2012, Labor says.

As part of the campaign, Sibelco orchestrated a massive letterbox drop lobbying voters in the seat to oppose the phase-out.

Opposition environment frontbencher Jackie Trad has written to the Crime and Misconduct Commission’s acting chairman Ken Levy asking for an investigation.

In her letter, Ms Trad said Natural Resources and Mines Minister Andrew Cripps had met with Sibelco on eight occasions over a two-month period but saw the indigenous Quandamooka people only once.

“Evidence collected by the Labor opposition and the Quandamooka people, as well as the perspective from a senior legal counsel in Queensland, indicate that preferential treatment may have been given to the mining company Sibelco at the expense of the Quandamooka people,” she told reporters.

“I believe there is sufficient evidence to warrant an investigation.”

The LNP promised to extend sand mining on North Stradbroke Island before winning the 2012 election.

Queensland Environment Minister Andrew Powell says locals wanted a slower shift to a new economy.

“It is no secret that we went into the last election with a more progressive, transitional transition from sand mining on North Stradbroke Island to a future industry, whether that be tourism or another,” Mr Powell said.

“We gave a commitment to sit down with Sibelco to work through a better transitional move that saw better environmental gains and that’s what is going in place now and it has my full support.”

Agriculture Minister John McVeigh said the opposition was only involving the Crime and Misconduct Commission because of the looming Stafford by-election.

“They’re simply using it as a toy, using it as a distraction for their own lack of policy,” he told reporters.