BHP Billiton is likely to delay final approval of the Olympic Dam mine until 2014 and has enacted a recruitment freeze on the expansion project.
According to The Australian final approval for the expansion has been put on hold for two years.
While The Australian attributed the rumour to a BHP consultant's document the company itself has yet to confirm the delay.
South Australian Premier Jay Weatherill told The Australian he had received no communication from BHP about the project and still expected a decision by the end of the year.
Earlier this year analysts tipped BHP may look to push back the massive expansions and the company said it was "looking for a decision before the end of the year".
Under current contracts BHP needs to commit to the Olympic Dam expansion before the end of the year or it will lose Government approval.
Earlier this year SA mineral resources minister Tom Koutsantonis said he may grant an extension under the right conditions.
"I will not grant BHP an extension just because they may want one," he said.