A human rights group says Venezuelan authorities have transferred a U.S. filmmaker accused of espionage to a notoriously unruly prison where more than 20 inmates were killed in a 2011 riot.

Patricia Andrade of the Miami-based Venezuela Awareness Foundation says Timothy Tracy was moved Wednesday from the secret police lockup in Caracas to the El Rodeo II prison. She says her sources are relatives of other transferred prisoners she cannot name for security reasons.

El Rodeo II was controlled by armed, drug-dealing gangs before the 2011 riot. Afterward, inmates held it for nearly a month.

Tracy was making a film about Venezuelan politics when arrested April 24 at Caracas' airport. U.S. President Barack Obama has called "ridiculous" Venezuela allegations Tracy was a spy or trying to destabilize the country.