From “The Yankee Comandante” by David Grann in the New Yorker:
To this day, some scholars, and even some who knew Morgan, speculate that he was sent to the Escambray by the C.I.A. But, as declassified documents reveal, Hoover and his agents had discovered something more unsettling. Morgan was not working for the agency or a foreign intelligence outfit or the Mob. He was out there on his own.