He had spent 11 years in Venezuelan prisons on charges he was involved in the bombing of a Cuban jetliner in 1976 in which 73 people were killed.

The fourth defendant, Luis Posada Carriles, a nationalized Venezuelan from Cuba, escaped from a Venezuelan prison in 1985, and has not been found.

About three out of four people in Venezuelan prisons have not been convicted.

On 20 August 2012, armed prisoners in the Yare I prison complex, an overcrowded Venezuelan prison, rioted over the weekend, resulting in the deaths of 25 people.

Mr. Posada spent nine years in a Venezuelan prison during trials and retrials on charges that he conspired to bomb the Cuban airliner.

"He served 11 or 11 1/2 years in a Venezuelan prison for a crime he didn't commit," Mr. Adorno said.

The fourth, Orlando Bosch, spent 11 years fighting the charges from Venezuelan prisons, was never convicted, and finally was released and returned to the United States last February.

It is true that her detention conditions are absolutely terrible, like those in all Venezuelan prisons.

As you know, dozens and dozens of prisoners have died in a Venezuelan prison in truly dreadful circumstances.

Backing the charge with statistics, the London-based human rights group said that from January 1990 to April 1994, 2,138 inmates were killed in Venezuelan prisons.