Atlanta ? Burger King Corp. has received a subpoena from a federal grand jury investigating allegations of fraud at Coca-Cola Co., a Burger King spokesman said Wednesday.

Rob Doughty would not say when the subpoena was issued or what documents it covered, but he confirmed it was related to an investigation by the U.S. Attorney into claims that Coke employees rigged a marketing test of Frozen Coke.

Neither Coke nor the U.S. Attorney’s Office in Atlanta, where Coca-Cola is based, would comment on the subpoena.

“We’re not going to go beyond our statement of July 11, that there is an investigation and that we are cooperating in it,” Coke spokesman Dan Schafer said.

The investigation was spurred by a civil lawsuit filed in May by former Coke manager Matthew Whitley that claimed Coca-Cola rigged a marketing test of the popularity of the new drink.

In June, Coke acknowledged that some of its employees undermined the test of Frozen Coke three years ago at Burger King restaurants in Virginia. It said the workers had been disciplined.