Mitt Romney's private equity firm, Bain Capital has been revealed to use obscure techniques to avoid paying U.S. taxes by using Cayman Islands-based funds according to recently leaked documents.

Over 900 pages of private audit and finance records from Bain were made public on the website Gawker today and offered up tantalising glimpses of the labyrinthine methods the Republican presidential candidate employs to pay less tax.

Some of the financial statements note the creation of 'blocker' funds, with statements on one noting that it 'intends to conduct its operations so it will not be subject to United States federal income tax or withholding tax.'