Frontline Action for Coal, an anti-coal group, had released the false statement causing a 9% decline in share value that translated into A$314m ($330m) loss in market capitalization
The hoax release led to Whitehaven investors selling their shares based on fears that mine development may come to a halt.
Whitehaven later refuted the hoax released and was backed by the ANZ bank.
"ANZ remains fully supportive of Whitehaven Coal," the bank clarified.
The Maules Creek coal project is situated in the Gunnedah Basin and is expected to generate an average annual saleable coal output of 10.8 million tonnes.
The mine is projected to begin producing coal in the third quarter of 2013.
