A Provari business prospectus claimed it had 150 production facilities around the island in 2001. Sanchez said it operates in virtually all of the estimated 200 prisons and labor camps in Cuba.
Prison labor is common around the world. In the United States, prisoners make license plates, government furniture and much more. Florida state prisons require inmates to work unless they are exempt for medical or other reasons. Most earn nothing, and canteen workers, barbers and a few others get only $50 a month.
"There's no objection in principle to companies managing factories in prisons," said Andrew Coyle of the International Centre for Prison Studies in London. But inmates should have equal salaries and work conditions. "This should not be forced or slave labor."
But Cuba is a dictatorship, Sanchez argued, where the communist government can do anything and keep it secret. That includes exploiting inmate workers at will and punishing anyone who complains.
He added that he was especially concerned about the safety conditions in prison factories and singled out the Lomate insecticide, manufactured in Havana's Combinado del Este and other prisons around the island.
Farm workers seldom get special clothing to protect them from chemicals, and cane cutters rarely get proper boots to protect their feet from their machetes, said Joel Brito, a former safety expert in the island's lone labor union, the Cuban Workers' Central.
"There are no protective measures because there's always a shortage of money. And if that's the case in the general economy, imagine what it's like for prisoners," said Brito, who now heads a Miami group that monitors labor abuses in Cuba.
Authorities allow only common criminals to work, fearing that political prisoners would publicize the work conditions, said Luis Enrique Ferrer, a dissident who spent eight years in prison. Ferrer, who did not work in prison, was freed in 2010 and now lives in Miami.