The trial of a Russian dissident accused of making and possessing thousands of indecent images of children has been stayed due to his ill health.
Vladimir Bukovsky, 75, denies five counts of making indecent images of children, five of possessing indecent images of children and one of possessing a prohibited image of a child.
The trial had been fixed for the third time at Cambridge Crown Court when Judge Gareth Hawkesworth granted the application to stay proceedings on Monday.
Mr Bukovsky was not in court during the brief hearing, which was due to be the start of his trial.
A first trial in 2016 was halted as Mr Bukovsky was admitted to hospital after its second day, and a second trial fixed in 2017 did not go ahead as he was again taken to hospital shortly before its planned start.
Francis FitzGibbon QC, defending, said Mr Bukovsky had "serious illnesses of the heart, lungs, liver and kidneys".
Judge Gareth Hawkesworth said that before the first trial was halted, Mr Bukovsky "kept falling asleep physically in front of the jury".
He said: "I'm quite satisfied that due to the continued deterioration in his health... when it came to the moment whether Mr Bukovsky should or could give evidence we would be faced with a wholly impossible situation.
"It wouldn't be fair to try the man in those circumstances."
He granted the defence's application to stay proceedings, which was invited by prosecutor William Carter.
"All matters will lie on file and cannot be revived without leave of this court or the Court of Appeal," said Judge Hawkesworth. "If his health recovers sufficiently for him to stand trial the matter could be revived."
Russian-born Bukovsky, an author and activist who became well known internationally as a vocal critic of the Soviet regime, returned to the UK from Germany to face the charges.
He had been receiving private medical treatment abroad, and is listed at a Cambridge address in court records.