The main trade association for the fantasy-sports industry received a grand jury subpoena Friday in an ongoing federal investigation of the legality of the fantasy sports business. Pictured: Mark Ingram of the New Orleans Saints is hit by Paul Worrilow of the Atlanta Falcons during the fourth quarter of a game at the Mercedes-Benz Superdome on Oct. 15, 2015, in New Orleans. Getty Images

The Fantasy Sports Trade Association received a grand jury subpoena Friday from a U.S. attorney's office in Tampa, Florida, according to the Wall Street Journal. An investigation by the Department of Justice and the FBI has reportedly been underway to determine the legality of daily fantasy sports games and whether they should be considered a form of gambling.

The announcement comes one day after the Nevada Gaming Control Board said unlicensed daily fantasy sports in the state must cease and desist, according to reports. The notice to licensees stated that daily fantasy sports (DFS) meet the requirements of a game or gambling game.