A Russian dissident accused of making and possessing thousands of indecent images of children is too unwell to stand trial, a judge has ruled.
Vladimir Bukovsky, 75, denies 11 charges in relation to child image offences and his trial at Cambridge Crown Court was due to begin on Monday.
The judge ordered the court to bring the case to a halt but if his health recovers the matter "could be revived".
Mr Bukovsky has "serious illnesses of the heart, lungs, liver and kidneys".
He was accused of 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.
A first trial of Mr Bukovsky, an author and activist who became well known internationally as a vocal critic of the Soviet regime, was halted on its second day after he was admitted to Addenbrooke's Hospital with pneumonia.
Judge Gareth Hawksworth said during that trial Mr Bukovsky, who lives in Cambridge, "kept falling asleep physically in front of the jury".
A second trial attempt last year did not start as he was admitted to hospital shortly before its planned beginning.
Judge Hawksworth 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.
"If his health recovers sufficiently for him to stand trial the matter could be revived."
A CPS spokesperson said: "Following a further decline in Mr Bukovsky's health the prosecution did not oppose the defence application to stay the proceedings.
"This does not mean the case has been dropped but is an order of the court bringing a case to a halt."