Consulting firm hired by Bill Ackman responds to report that the Feds are investigating them for lying about Herbalife

Global Strategy Group, the consultancy firm hired by hedge fund manager Bill Ackman, said they are not the target of any investigation into potential manipulation of Herbalife's stock.

"It is our clear understanding that we are not a target of any investigation, and we are confident that all our work surpasses the highest legal and ethical standards. We spoke with the government and provided full transparency into all of our efforts. GSG has never made false statements about Herbalife, nor do we believe anyone else has either," the firm said in a statement emailed to Business Insider.

The Wall Street Journal reported on Thursday that the Manhattan US attorney's office and the FBI have done interviews with contractors hired by Ackman as to whether or not they made potentially false statements about Herbalife to regulators.

Ackman told CNBC on Friday morning that neither he nor his fund has been contacted by the FBI.

He said that he was aware that Global Strategy Group had been contacted. Global Strategy doesn't lobby, but contracts out to state and federal lobbyists, according to a source.

Ackman, who runs $19 billion Pershing Square Capital, is infamously and very publicly short Herbalife-a multi-level marketer that sells nutritional shakes and supplements. It's Ackman's belief that the company operates as an illegal "pyramid scheme" that targets lower-income people. He's betting the stock goes to $0.