The NSW Department of Planning is investigating the seemingly phantom appointment by Whitehaven Coal of an environmental group to a compulsory oversight committee for its $767 million Maules Creek coalmine.

The department warned Whitehaven in June 2013 after its nominated group, Greening Australia, failed to send a representative to the inaugural meeting of the Community Consultative Committee due to discuss the open-cut mine's biodiversity management plan.

Maules Creek dispute: A green group was surprised at its nomination to an oversight committee.

"I would remind you that the intention of including a representative from an environmental special interest group is to ensure sufficient comment and feedback on biodiversity issues," mining projects manager Mike Young wrote to Whitehaven, according to documents obtained by New Matilda and viewed by Fairfax Media.

Despite the request a representative of Greening Australia provide comments "either in writing or at the next CCC meeting", Whitehaven failed to act. Instead, the miner provided "apologies" for the group's absence at all subsequent meetings.