A statue has been inaugurated in Bulgaria to the dissident playwright Georgi Markov, who was assassinated in London in 1978.
Markov, who worked at the BBC World Service, was poisoned, apparently on the orders of Bulgaria's then communist authorities.
A pellet containing a toxin was fired into his leg on Waterloo Bridge, possibly from an umbrella.
The statue was unveiled by President Rosen Plevneliev.
Speaking at the ceremony in Journalist Square in central Sofia, Mr Plevneliev said: "The words of Georgi Markov spiritually liberated the Bulgarians even before the toppling of the communist regime."
Those who attended the ceremony included Markov's widow Annabel, who spoke of how he her late husband had longed to go back to Bulgaria.
He has now returned to Bulgaria "as a permanent part of the landscape of Sofia", she said.
Markov was waiting for a bus on Waterloo Bridge when he felt a sharp jab in the leg and saw a man nearby dropping an umbrella.
After developing a fever, he died five days later in hospital on 11 September, aged 49.
The pellet, possibly containing ricin, is thought to have been fired either from the umbrella or a pen into his thigh.
The killing is assumed to have been carried out on the orders of the Bulgarian secret service, possibly with help from the Soviet KGB, to silence his radio broadcasts. But investigations have failed to prove this conclusively.
The Bulgarian authorities closed their investigation into the incident last year and a British police inquiry remains officially open.
No-one has been formally accused of the killing, but Bulgarian police files which came to light spoke of an agent codenamed "Piccadilly".
Markov went into exile in 1969 and became an outspoken critic of the Bulgarian communist government of the time.
The incident is one of the most notorious of the Cold War, which saw communist Russia and the United States face each other across a divided Europe in a state of deep mutual suspicion.