LONDON — As Mark Feldstein, the first witness on the first day of the high-stakes extradition hearing for Julian Assange, appeared by video link from his home recently, reporters following the case remotely and those watching in an adjoining court could see and hear him.
The judge and others in the main courtroom, however, had no idea what he was saying.
The hearing, taking place in the Central Criminal Court in London this month to decide whether the embattled WikiLeaks founder should be extradited to the United States, is one of the most crucial junctures yet in a legal fight that began nearly a decade ago.
But since it began in February the case has been stymied, first by the pandemic, which pushed it back by several months, and now by a string of technical glitches. Since the high-profile hearing resumed last week, the court has been forced to adjourn on several occasions while staff members try to address problems with the livestream and video conferencing.
With the onset of the pandemic, the court, known as the Old Bailey, began conducting much of its proceedings online. Because of travel restrictions, several witnesses were unable to testify in person, and limited seating because of social distancing has forced many court observers to witness the hearing through video streamed to overflow areas outside the courtroom.
The technical difficulties have drawn complaints from court observers and rights advocates who say that their ability to monitor the proceedings has been hampered.
The problems are all the more vexing in a trial that is centered around the technically sophisticated world of hacking and the release of a trove of secret documents on the internet.
The court took a break to try to fix the problems with the witness’s video link, but the difficulties only worsened, forcing another adjournment. Some days later, the hearing was delayed further over fears that a lawyer for the prosecution might have come into contact with someone with the coronavirus.
The lawyer ultimately tested negative for the virus and the trial resumed on Monday. But technical difficulties again hampered the day’s agenda, with another witness inaudible on the livestream.
Rebecca Vincent, the director of international campaigns for Reporters Without Borders, who was in the court this week, said there had “constantly been problems,” with the livestream of the main courtroom cutting out and witness testimony frequently garbled.
Ms. Vincent explained how Eric Lewis, a United States-based attorney acting as a witness for the prosecution, was inaudible during his testimony on Monday, with the court trying and failing for two hours to establish a usable video connection before adjourning for the day.
Things were little improved on Tuesday.
“There was rarely an extended stretch of time when I could adequately hear what was going on,” Ms. Vincent said, owing to a buzzing noise in the public gallery and an echo on the livestream in the viewing area.
On Wednesday, the first witness testimony conducted by video link — with John Goetz, an investigative journalist — began with some shaky moments but eventually settled down, and his testimony was largely audible.
The afternoon testimony of Daniel Ellsberg, the former military analyst who leaked the Pentagon Papers in 1971, was also smooth for the most part.
But Ms. Vincent noted that the issues had already affected the proceedings in a number of ways, making the situation “insufficient for observation and to ensure open justice.”
From the start, press freedom advocates and rights groups have denounced the charges against Mr. Assange, saying that they raise profound First Amendment issues because the publication of the classified material is indistinguishable from the practices of traditional news organizations.
Mr. Assange, 49, was arrested in London last year after being expelled from the Ecuadorean Embassy, where he had spent seven years behind a veil of diplomatic immunity.
The United States has indicted Mr. Assange on 18 counts of violating the Espionage Act for soliciting, obtaining and sometimes publishing material that the government deemed classified, in connection with the release to WikiLeaks of archives of military and diplomatic documents by Chelsea Manning, a former Army intelligence analyst.
Mr. Assange is not facing charges over the later publication by WikiLeaks of Democratic emails stolen by Russian hackers in the 2016 U.S. election.
In addition to the technical problems, rights groups complained that a number of international observers had been denied access to the courtroom in an official capacity and that their access to the remote livestream had been revoked.
Some, like Ms. Vincent, have been allowed to sit in an overflow courtroom open to the public, where the witnesses are shown on video. But she said she worried that the technical issues were just the tip of the iceberg.
“What we are seeing now, this week, you can’t really divorce the tech issue from the other restrictions on observers,” she said.
During the first phase of the hearing in February, Amnesty International and other observers had been granted permission to attend the hearing as official monitors.
This time around, that has changed, according to Julia Hall, Amnesty International’s expert in counterterrorism, criminal justice and human rights in Europe. Her organization requested access to the courtroom, she said, but was initially allowed access only to a livestream to view the hearing remotely. But last week, that was abruptly revoked when the hearing began.
“This situation that we are in right now is quite disturbing, and it’s unique,” Ms. Hall said. “This court has failed dramatically to recognize a key component of open justice, and that is how international trial monitors monitor a hearing for its compliance with domestic law and international law.”
Barring further delays, the hearing is expected to be finished by early October.
When asked about the issues during Mr. Assange’s hearing, a spokesman for Her Majesty’s Courts and Tribunals Service, which administers the court, offered only a general statement.
“We work hard to ensure that any technical issues are identified and repaired as soon as possible,” the spokesman said. The Ministry of Justice, when asked for comment, directed requests back to the courts service.
In June, the ministry announced plans for an additional 142 million pounds, about $183 million, to help speed up technological improvements and modernize courtrooms.
Several requests for comment from lawyers for the prosecution and from Mr. Assange’s defense lawyers on the impact of the technology issues have gone unanswered. But rights groups assert that, because of the implications for press freedom, the issues must be resolved immediately.
“This case is of tremendous international public interest as it has ramifications in not just the U.S. and U.K. but internationally,” Ms. Vincent said.
Charlie Savage contributed reporting from Washington.