The department would also be investigating the timing of Aston’s political donations around the time of the application to determine if it adhered to legal guidelines.

Aston is currently embarking on a proposed $6 billion merger with Whitehaven Coal and Boardwalk Resources, Nathan Tinkler’s private company.

“The Planning Assessment Commission has been asked to review the Maules Creek project and hold a formal public hearing for interested parties, prior to the department completing its assessment,” the department said in a statement.

“This report will be considered by the department and once the department has finalised its assessment report, the matter will then be referred to the PAC to determine.”

“Regardless of whether there were political donations, the application will be determined by the independent PAC under delegation.”

The department said Aston submitted a political donations disclosure with its application in 2010, indicating there were no donations to declare.

In November 2011 the department was again advised there was nothing to declare.

Section 147 of the Environmental Planning and Assessment Act requires proponents to declare political donations made within two years of the application by the company, a related corporation (including a holding company), or company directors.

The proponent is also required to disclose any subsequent political donations after the initial application is lodged, within seven days of the donation being made.

The department said the legislation placed the onus on applicants to disclose political donations.

If Aston is found to have breached its obligations under the act, the department said it would decide what further action to take.