Some "banks excluded certain bonds, and many reduced the sums to account for 'short' positions they held—facts that neither regulators nor most banks disclosed when the test results were published in late July," according to the article.
The paper writes that it is impossible to gauge the number of banks that excluded part of their sovereign debt holdings, but singles out Barclays and Credit Agricole, which the paper claims reduced by a significant amount their exposure to government debt.
Barclays and Credit Agricole said they were acting in accordance with the rules set out by the European authorities, the paper wrote.
Pedro De Noronha, managing partner at Noster Capital, told CNBC last week that the stress tests made him laugh.
"We only stress tested what the banks told us, I did not see anyone testing until they had gone broke," said Noster who is shorting five major European banks.
"When I look at Tier 1 capital ratios, I find things propping them up that are not assets that can be drawn on in a crisis," he said. "The real capital 1 ratio of some major banks is just 1.7 percent."
Following the release of the stress tests on July 23rd, when only seven banks of the 91 tested failed, investors' attention came off the banks and turned towards issues in the US and Chinese economies.