He added “As we previously stated, we consider the documents to be highly relevant to our claims against RBS as they relate to the question of RBS' role in S&P's rating of the mortgage-backed securities at issue in the litigation against RBS.”

Tschudy clarified statements made in other trade publications that included claiming CUNA Mutual's suit questioned the role of rating agencies. Rather the company's claim “is about the misrepresentations made by RBS to us,” he noted.

Tschudy also said statements regarding CUNA Mutual's filing of motions to compel against Fitch Ratings and Watterson Prime LLC resulting in the production of records connected to the failed investments are not accurate, as had been previously reported elsewhere.

In March, CUNA Mutual asked the U.S. Court for the Western District of Wisconsin to issue an order that would require RBS to buy back $72 million in failed residential mortgage-backed securities. The securities were sold to CUMIS Insurance Society and MEMBERS Life Insurance Co., both subsidiaries of CUNA Mutual in Madison, Wis.

In that motion, CUNA Mutual said CUMIS invoked a right of rescission that would require RBS buy back the mortgage-backed securities.

Between 2004 and 2007, CUNA Mutual said RBS “induced” it to buy 15 certificates in 10 separate RMBS offerings by making representations about the credit quality of the pools of mortgage loans collateralizing those RMBS, according to CUNA Mutual's complaint.

CUNA Mutual said it relied on RBS's quantitative representations in deciding to purchase 15 certificates in the 10 separate RMBS offerings. After CUNA Mutual's purchases, all 10 of the securities performed poorly and the 15 certificates have since lost much of their value, according to the complaint.

CUNA Mutual said it is seeking to recover $72 million, the amount it would take for RBS to buy back the failed RMBS.

Before it filed the lawsuit, CUNA Mutual said it commissioned a forensic investigation of the loan pools collateralizing the 10 RMBS to test the accuracy of RBS's quantitative representations.

It sampled 17,949 loans from each transaction and conducted a retroactive appraisal using valuation models and historical data to test RBS's representations about LTV and CLTV ratios. CUNA Mutual also analyzed public records to test RBS's representations about owner occupancy rates.

CUNA Mutual said its investigation revealed that RBS's quantitative representations in the offering documents of the 10 RMBS were false at the time they were made. Specifically, RBS “dramatically understated the LTV or CLTV ratios of the loan pools underlying the 10 RMBS.”