Late Wednesday evening, Senator Marco Rubio confirmed rumors on Twitter that Leopoldo López, the head of Venezuela’s opposition Popular Will party, had been transferred from prison to a military hospital in “very serious” condition.

López is currently serving a fourteen-year prison sentence for organizing peaceful protests in 2014 against the socialist dictatorship of Nicolás Maduro, a bus driver who succeeded Hugo Chávez after his death in 2013.

Senator Rubio posted that he had confirmed the rumors on Twitter, and addressed a tweet to President Donald Trump noting that López’s condition appears to have deteriorated significantly since his wife, Lilian Tintori, visited the White House to call for help in freeing him.

Tintori also announced on Twitter that she was heading to the military hospital in question to confirm the news. “#URGENT At this time I am on the way to the Military hospital to demand to see Leopoldo,” she wrote in Spanish.

Videos of her arrival began to appear on the social media platform shortly thereafter:

Following her arrival at the hospital, however, Tintori tweeted that officials told her López was not present in that building.

“Captain Rodríguez informs [us] that Leopoldo is not here. We want to know the truth. Enough with this pain! We want to see Leopoldo!” she tweeted.

Videos have surfaced showing authorities denying her entry into the military hospital:

The rumors appeared to originate from a tweet by journalist Leopoldo Castillo, who suggested that the Maduro regime would blame “intoxication” for López’s condition and that López had entered the hospital “without vital signs.” Castillo did not clarify what he meant by “intoxication,” though he reiterated on Twitter that he had “not been hacked” shortly before Senator Rubio confirmed López’s transfer out of the notorious Ramo Verde prison, where he had been serving time in solitary confinement.

While Senator Rubio says he has confirmed the news, Univisión reported that it contacted the dissident’s attorneys, who could not independently confirm where López was or whether his health was in jeopardy. The Venezuelan website La Patilla also cited his attorneys as saying they could not independently confirm his status. “There is no way of confirming it,” attorney Juan Carlos Gutiérrez said. “There exists no way of contacting him.”

Last week, Tintori denounced the government for forbidding her from seeing her husband. Tintori told reporters on a Periscope broadcast that she had not been able to see López in three weeks and that his attorneys had also been unable to see their client. “They don’t tell us why [we can’t see him], just that it is an order from above,” she said.

The news broke during the state television program Con El Mazo Dando (“Hitting with the Mallet”), hosted by National Assembly minority leader and suspected drug kingpin Diosdado Cabello, who lost his position as the nation’s second-in-command when the Socialist Party (PSUV) lost its majority in the assembly in 2015.

On his program, Cabello denied the rumors that López’s health was in danger, referring to the opposition leader as a “monster.”

“Now I am being told that they are making up that we did I don’t know what to the Ramo Verde monster. No, no one has done anything to the Ramo Verde monster,” Cabello said, referring to the prison. Cabello also repeatedly the government’s claim that López, by organizing peaceful marches against the government, was responsible for the deaths of those killed by police brutality during the wave of 2014 protests.

Cabello later broadcast a “proof of life” video he claimed to have been recorded earlier this evening, in which a man identifying himself as López appeared and gives the date and time, claiming it to be 9:00PM local time despite the apparently daylight behind him. “I don’t understand why they need proof of life at this time,” the man says.

Leopoldo López, who turned 46 on Saturday, is the Harvard-education son of Venezuela’s elite, with a direct descendancy to the nation’s founding father, Simón Bolívar. He had long been a thorn in the side of the Chávez regime as a political opposition leader, and had been banned by the socialist regime from holding public office in 2004. He nonetheless attempted to run against Chávez in a 2011 presidential election and, following his death, continued to organize a resistance movement against Maduro. While he opposed the nation’s socialist leadership, López himself and his party, Popular Will, are members of the Socialist International.

Maduro’s government issued a warrant for his arrest in February 2014, following the organization of a series of protests against the regime. López peacefully handed himself over to authorities in Caracas on February 18 of that year. In his final tweet before handing himself over to authorities, he wrote: “I am logging off. Thank you, Venezuela. Change is within every one of us. Let us not give up. I won’t!”