In a midafternoon Facebook post, Joshua Holt, a US citizen and missionary whose family has said he was framed on weapons charges while in Venezuela for his wedding, said, "Helicoide the prison where I am at has fallen the guards are here and people are trying to break in my room and kill me".
Political prisoners have always been complaining about the conditions they are held in and pressure groups inside Venezuela as well as overseas have called on the government of President Nicolás Maduro to free them but so far this has had little impact. "How long do I have to suffer?" I need your help to get me out of this place.
"We're demanding that all political prisoner be freed, all of us who have been held here, kidnapped for years without justice or due process", he told CNN via telephone from inside the jail.
In three short clips, a visibly distraught Holt makes a plea for help from his fellow Americans, and suggests that his patience is running out with the U.S. government after close to two years behind bars.
The couple were arrested at her family's apartment in Caracas after police alleged he was stockpiling weapons - an assault weapon and grenades - accusations which have been refuted by Mr Holt and his family.
Today, I learned Josh Holt was enduring a riot situation in his Venezuelan jail.
Relatives of inmates react outside a detention centre, where a riot occurred, in Caracas.
Image Relatives of inmates react to word of riots at the El Helicoide facility
In a third video circulating on social media, the American is seen standing calmly next to three well-known opposition activists wearing the same black T-shirt he had on earlier Wednesday. While he didn't provide details about the disturbance, or what sparked it, he said on Twitter that the delegates offered to coordinate with prison and judicial authorities to address the demands of inmates at El Helicoide, which is the headquarters of the feared Sebin intelligence police.
Venezuela's Information Ministry did not respond to a request for comment. Venezuelans will be voting for a new president on Sunday.
Rights groups and Maduro opponents have said several hundred political prisoners have been unfairly jailed.
"We are concerned about the riot at El Helicoide", Mr Robinson said in a statement, referring to the helix-shaped building where Maduro's top opponents are being held.
The U.S. embassy in Caracas said it was "very worried" about the situation at the Helicoide. His family has denied the accusations, and believe the Venezuelan government is holding Holt and his wife to bargain with the US, which has imposed economic sanctions on the country.
The Trump administration has warned that it could put crippling oil sanctions on Venezuela if Maduro goes ahead with what the US and others consider a sham presidential election Sunday.
"The life of Joshua Holt is in danger and we call again on the government to release him for humanitarian reasons", the embassy wrote in Spanish.