The Construction, Forestry, Mining, and Energy Union has accused BHP Billiton of running a secret plan to reopen the Norwich Park mine with a de-unionised workforce.
In a statement yesterday the CFMEU said it had obtained a document that indicated BMA had a five year plan to restart operations at Norwich Park with different employees.
CFMEU district president Stephen Smyth said BMA needed to "come clean" on its plan for the mine and its staff.
"Workers already held fears that BHP's decision to close Norwich Park may not have been purely for the operational reasons the company cited," he said.
"Having a document turn up apparently showing BHP has a five-year plan to employ new workers at a mine that is supposed to be closed in eight days does nothing to allay these fears."
BHP was not available for comment late yesterday but told reporters there was no plan to reopen Norwich Park.
The company said the reasons for the mine's closure were made public after the initial announcement was made and have remained unchanged.
BHP said the union's comments were the "latest attempt to mislead BMA's employees" and needed to be viewed in the context of other union battles in the Bowen Basin.