Former Soviet dissident Vladimir Bukovsky is in an induced coma in a private German clinic after undergoing emergency surgery on his heart.
Bukovsky's friends told RFE/RL's correspondent in London on May 7 that the veteran human rights activist underwent a nine-hour surgical procedure in a Munich clinic, where two of his heart valves were replaced.
The surgery went smoothly, and Bukovsky's condition is no longer critical, the clinic's doctors were quoted by Bukovsky's friends as saying. However, Bukovsky's life is still at risk, and he will remain in a coma for another three days, doctors said.
The surgery came after British prosecutors announced last week that Bukovsky is suspected of making and possessing indecent images of children, accusations he has publicly rejected.
Bukovsky, who faces 11 charges related to the allegations, was supposed to be charged in court on May 5, but the hearing was postponed after his health deteriorated.
He said in an April 27 statement that he "absolutely denies" the accusations and will "vigorously defend" himself against them.
Bukovsky has been seriously ill since last year, when he contracted a rare infection that subsequently damaged his heart valves. His condition worsened significantly this week when he suffered multiple internal organ failure.
Bukovsky, 72, has lived in Britain since 1976, when the Soviet Union exchanged him for Chilean Communist leader Luis Corvalan.
He has been harshly critical of Russian President Vladimir Putin and accused the Kremlin of involvement in the 2006 radiation-poisoning death of former Russian intelligence officer Aleksandr Litvinenko in London.
Bukovsky -- who attempted to run in the 2008 Russian presidential election -- told RFE/RL last year that Russian Embassy officials had refused to renew his Russian passport because of his anti-Putin comments.
First arrested in the early 1960s, Bukovsky spent 12 years in prisons and psychiatric hospitals for his activism and "anti-Soviet agitation and propaganda."
He was among the first to report the Soviets' use of psychiatric institutions to punish political prisoners.