There is no evidence to support claims the former Newman government reversed its decision to oppose the expansion of the Acland mine because of political donations, Queensland's corruption watchdog has found.

Anti-mining group Lock the Gate Alliance lodged a complaint with Queensland's Crime and Corruption Commission (CCC) in August alleging the Liberal National Party Government's approval of the expansion of the mine, west of Brisbane, was influenced by gifts and donations.

The ABC revealed last year the mine's proponents New Hope Group and its Australian parent company, Washington H Soul Pattinson, had donated $700,000 to the Queensland LNP and the federal Liberal Party over a three-year period.

The CCC has determined it will not investigate the matter, after assessing "a large volume of information".

"Based on the thorough assessment of the available information, the CCC considers there is insufficient evidence to support the allegations and insufficient evidence to raise a reasonable suspicion of any criminal offence," it said in a statement released on Friday.

"The CCC will therefore take no further action."

The mine's expansion would increase annual output from 4.8 million tonnes to 7.5 million tonnes, with proponents New Hope Group arguing the project would create hundreds of jobs and boost the local and state economies.

Opponents, including landholders, claim the mine expansion will worsen air quality, swallow up nearly 1,400 hectares of strategic cropping land and cause groundwater to drop by almost 50 metres in some places.