He has said that he will not release more than two years and is following the precedent set by Sen. John McCain during the 2008 election.
The newly released documents rekindle questions about one of the more technical tax questions that has emerged about Romney's investments – the use of so-called "blocker" entities. The blocker is a paper company that serves as a buffer between the investor and the fund holding the investments, Wilkins explained. That means the investment income can be counted as a dividend and in some cases avoid income tax.
In the financials for the Bain Capital Asia Fund, for instance, the audit describes the establishment of blocker corporations to hold more than $92 million in contributions from the fund.
Some experts have pointed to the blockers to help explain how Romney has been able to amass between $20.7 million and $101.6 million in a tax-free IRA, many times more than the typical amount an IRA can hold. Romney has not responded to questions about his IRA.