The blood-clotting drug, called Factor VII, has been shown to be ineffective in clinical trials and been the focus of safety warnings by U.S. and European regulators, The Baltimore Sun reported Sunday.
The U.S. Food and Drug Administration has approved the drug only for the treatment of rare forms of hemophilia, the newspaper said.
The drug, which is suspected of causing fatal blood clots, cannot legally be used in the United States for treating trauma because that is not among its FDA-sanctioned uses, regulators say.
Army sources say the investigation is focused on the Army's research methods and its financial arrangements with the drug's Danish maker, Novo Nordisk, who markets it under the trade name NovoSeven at more than $6,000 per dose.
"We do not know the specific reason or scope of this investigation," Novo Nordisk's chief financial officer Jesper Brandgaard said. "The thing we are aware of is that U.S. Army doctors have, at their discretion, been using NovoSeven and the U.S. Army had been purchasing NovoSeven for trauma use (with) soldiers."