WikiLeaks founder Julian Assange missed a scheduled court hearing via video link on Thursday because of illness, his lawyer told British media outlets.

Defense lawyer Per Samuelson was quoted by WikiLeaks as saying that Assange’s health had deteriorated to an extent that made it “not possible to conduct a normal conversation with him.” The details of Assange’s illness remained unclear, but WikiLeaks has voiced concern about what the group called a grave health condition.

Assange, 47, was arrested inside the Ecuadoran Embassy in London last month after that nation said it would no longer grant him refuge because he had repeatedly violated its rules.

The WikiLeaks founder was originally wanted in Sweden in connection with rape and molestation allegations in 2010. Assange denied the accusations, but he was subsequently arrested in London on behalf of the Swedes and later released on bail.

In 2012, a British court ruled that Assange should be extradited to Sweden. Accusing Swedish authorities of using the allegations as a pretext for a more political investigation by U.S. prosecutors, the WikiLeaks founder sought protection in the Ecuadoran Embassy, where he stayed for the following seven years — unable to leave the embassy grounds without risking arrest.

After his arrest in London this April, Assange was sentenced to 50 weeks in jail for jumping bail in 2012. He still faces an investigation in Sweden.

But the charges that could prove to be most dire for him were brought in the United States.

Assange appears to have been correct in assuming that U.S. prosecutors would investigate him in connection with his interactions with then-Army intelligence analyst Chelsea Manning, who shared classified documents with WikiLeaks. On the U.S. side, Assange initially faced a conspiracy charge related to his ties to Manning.

Last week, he was additionally charged with violating the U.S. Espionage Act, which significantly upped the stakes of his case. The Trump administration’s decision to charge Assange under that act for seeking classified information sent a chilling message to press freedom advocates, some of whom said the same rationale could be used to charge investigative journalists in the future.

U.S. officials rejected that criticism, arguing that there were significant differences between WikiLeaks and news organizations.

“Julian Assange is no journalist,” said John Demers, U.S. assistant attorney general for national security.

WikiLeaks has contested that assertion, describing the charges as “an unprecedented attack on the global free press” by the Trump administration.

Assange’s next hearing is scheduled for June 12.

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