By Emily Flitter Reuters July 2, 2012 NEW YORK, July 2 (Reuters) - A U.S. Securities and Exchange Commission investigation into the accounting practices of Green Mountain Coffee Roasters is casting a spotlight on M. Block & Sons, a little-known consumer products distributor. The 18-month Green Mountain probe marks the third time in a dozen years that securities regulators have looked at the accounting practices of a company that used Chicago-based M. Block to store and help deliver its products to major retailers. One of the previous investigations led the SEC to charge former Sunbeam Corp Chairman Albert Dunlap with overseeing a massive accounting fraud. The other case involved mobile technology accessories maker iGo Corp, whose executives were charged with inappropriately using M. Block's services to record revenues ahead of schedule. Neither M. Block nor any of its employees has been charged with wrongdoing as a result of the three investigations. B...