A VOCAL critic of the federal government's mining tax, billionaire Clive Palmer, did not have to pay tax in his main private company last year, according to accounts lodged with the corporate regulator.

The company accounts show Mineralogy and its subsidiaries reported losses for the past three financial years. The profit-and-loss statement shows no tax was payable in 2010-11.

Mining magnate Clive Palmer. Credit:Rob Homer

The losses come as Mineralogy's mining projects remain at exploration or development stage. Other parts of Mr Palmer's business empire, including Queensland Nickel and various property interests, are held outside Mineralogy.

The Mineralogy accounts underline the difficulty of valuing Mr Palmer's vast mineral deposits and therefore his personal wealth.