Have you tried the company registrars for Regal Petroleum? They have to keep the records of shareholders, so if it is in the name of Ballure Trading then it will be easy.
But if the stock is held in a nominee account, then you are unlikely to find out.
The name Ballure has strong connections with the Isle of Man, incidentally. Not that that is anything to go by, but Isle of Man has certain tax benefits, so there may be a connection.
The only other thing I would suggest is posting on an Australian stock trading board, to see if you can get any info from Oz.