Three years plus, and still the NSW Resources Regulator's investigation of whether Wollongong Coal is a "fit and proper person" to hold a mining licence is "ongoing".

The investigation started in Jully 2016 and has involved financial records among other compliance issues. But all requests to the Regulator for updates have drawn the same answer: "ongoing".

Since then, the miner has been probed by the ASX over concerns its assets may be overvalued, has had its Wongawilli operation shut down over safety breaches and roof collapses, has faced questions from its own auditors over its solvency, and its owner, Naveen Jindal, faces court cases in India over coal lease allocations (he pleads not guilty).

Some improvements have been made - a proper ecologist was hired to perform environmental studies, plus some respected mine managers. And an experienced mining consultant was hired to put together its application to expand under the water catchment from Russell Vale.

Government says the "fit and proper" policy exists because mining can be hazardous, with unacceptable impacts on the community or environment if done poorly.

"The right to access and develop the mineral and petroleum resources that belong to the people of NSW is a special privilege," it says, so mining should only be done by companies that "will respect that privilege".

Relevant matters could include compliance or criminal conduct issues, including environmental damage, evidence of a "a corporate culture that cannot be trusted", or evidence of ongoing financial difficulties - these may indicate a miner wouldn't be able to carry out obligations such as fee payments or rehabilitation work.

The "fit and proper" can be a low bar to clear. A conclusion of corruption by ICAC "would not alone be grounds" for a resources decision-maker to knock back a mining applicant, the policy states.

It's possible that the Regulator has substantially completed its investigation, but has not had a proposal to which to apply the result to an application.

The "fit and proper" policy spells out how adverse findings can have serious consequences for an applicant, and for business confidence, so decisions must be made on the basis of good evidence.

This caution is entirely reasonable.

But an investigation that says nothing for three years hardly builds confidence in our regulatory system, and raises questions that the policies exist in words only.

Surely it must be completed before assessment of further expansion can proceed.