While much of the focus on Gina Rinehart of late has been on her bid for cattle company S.Kidman & Co and her huge Roy Hill iron ore project, the mining billionaire also has investments in some small listed companies.

Rinehart, a perennial member of the top 10 names on the BRW Rich List and executive chairman of Hancock Prospecting, is among the top 20 shareholders on the register of two minnows in Lakes Oil and Sun Resources.