The Independent Commission Against Corruption (ICAC) has again heard of various attempts to conceal the links former New South Wales Labor ministers had to mining projects.
The inquiry has heard the Obeid family and its associates purchased properties in the coal rich Bylong Valley area of the Upper Hunter and also had a secret stake in companies that were awarded coal exploration licences.
Lawyer Philip Podzebenko said a director of mining company White Energy became angry at a 2011 meeting to discuss a $500 million coal deal with Cascade Coal.
He said after being unable to get straight answers about the Obeids' involvement in Cascade Coal the director stormed out of the room.
The deal later fell through.
Another witness, Warwick Grigor denied a "cover up" over the Obeid family's involvement in a mining company.
He said it was instead an, "incomplete disclosure".
The ICAC also heard that RAMS Home Loans founder John Kinghorn held shares in a coal company on trust for Greg Jones, a friend of former NSW mining minister Ian Macdonald.
The inquiry is likely to run for up to five months, with Ian Macdonald and Eddie Obeid expected to give evidence in January.
Commissioner David Ipp has adjourned the inquiry until Thursday.