Dewey Square Group is the latest PR firm (in this case, a public affairs firm) to find itself embroiled in allegations of unethical and illegal behavior on behalf of a client.

The PR firm, which is part of WPP, confirmed that it was hired by an unnamed client to send comment letters to the U.S. Commodity Futures Trading Commission (CFTC) about proposed trading rules Bloomberg reports. However, the firm said it hired a subcontractor, Goggans Inc, to help “build support” for a grassroots campaign it worked on and didn’t know the letters were fraudulent. The CFTC has turned the letters over to the Justice Department. The letters violate the False Statements Act; violating the act is a felony.

“Dewey Square had no reason whatsoever to believe that the letters were not authentic and had no knowledge that they were in fact unauthorized until questions were raised in media accounts,” Dewey Square principal Ginny Terzano is quoted saying in the story. (Updates after the jump.)

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