Bukovsky, 72, was a leading opponent of the former Soviet Union's use of psychiatric treatment to silence political prisoners. He spent years in Soviet jails, but moved to the British university city of Cambridge after a 1976 prisoner exchange deal between Moscow and Washington.
Britain's Crown Prosecution Service (CPS) said Bukovsky was charged with five counts of making indecent images of children, five of possession of indecent images of children and one count of possession of a prohibited image.
However, after failing to appear in court on May 5, Bukovsky was said to have travelled to Germany for an urgent operation. On May 7, media and Twitter reports stated that 72-year-old Bukovsky was in a medically-induced coma in a private German clinic after emergency surgery on his heart.
Following nine hours of surgery, where two of his heart valves were replaced, the doctors said the operation "went successfully", and while his life is still at risk, his condition is no longer "critical".
Bukovsky has vigorously declared his innocence, saying in a statement: "I categorically deny making any indecent or prohibited photographs, pseudo-photographs or sharing of information online which could in any way prejudice these proceedings.
"These shocking allegations have been made at a time when I am suffering from grave illness and my chances of survival are still uncertain. Nevertheless, I intend to defend myself vigorously on all charges."
He had been due to attend Cambridgeshire magistrates court on May 22, but, although his case was listed, his solicitor Jacqui Baldwin was not due to attend court, her firm Oslers Solicitors told Sputnik.
