According to the Daily Telegraph, a Dutch newspaper obtained the document - originally intended for publication earlier this year - via a freedom of information request and the EC has been criticised for its perceived prejudice against funds.
The study found "no conclusive evidence" that traders engaging in such swaps had significantly worsened the debt problems of struggling European countries and in fact praised the market for "encouraging risk-sharing".
"CDS spreads for the more troubled countries seem to be low relative to the corresponding bond yield spreads," it stated. "Government deficits, debt levels and current account deficits give a consistent picture of vulnerabilities."
Last month, the European parliament approved a range of new regulations aimed at curbing the activities of the trading bloc's hedge fund industry, despite concerns from the British government.