Records from the Australian Securities and Investments Commission (ASIC) showed that Ms Rinehart's Hancock Prospecting chalked up whopping profits of $688 million in June 2010, covering the financial year 2009-10.
Those numbers jumped almost twice as Hancock Prospecting profited $1.2 billion in June 2011, based on the holding firm's annual reports that covered two years of investment activities that Ms Rinehart belatedly filed on Dec 24 2012, the ASIC said.
As expected, the Australian tycoon much of her earnings from iron ore interests, which are largely represented by Hancock Prospecting's active partnership with global mining giant Rio Tinto.
The ASIC filing also showed that Ms Rinehart collected some $US735 in revenues from her late 2011 deal with investment group GVK of India, which turned over Hancock Prospecting's Queensland coal operations to Indian hands.
No specific liabilities were declared from the latest report, The Age reported on Friday, except for some legal issues within the group that likely will spawn financial obligations later.
However, the company assured on its ASIC filing "that there are no significant liabilities arising from such legal actions and claims that would have a material adverse effect on the consolidated financial statements."
Equally, Hancock Prospecting is upbeat of gaining more inroads in Australia's lucrative iron ore business via the Roy Hill project in Western Australia.
Ms Rinehart's group owns 70 per cent of the Roy Hill Holding, which is touted to operate one of the country's biggest iron ore mine and rail and port projects, according to The Age.
For all the revenue streams filling up Hancock Prospecting's coffers, its filings for the past two financial years, which notably skipped FY 2011-12, only showed dividend payments of over $18 million.