Bulgaria is closing its investigation into one of the most notorious political assassinations of the Cold War.
Georgi Markov, a prominent writer and journalist, fled Bulgaria in 1969 but continued to denounce the country's then-communist regime in reports for the BBC and Radio Free Europe.
On September 7, 1978, he was injected with a ricin-poisoned pellet by a passerby carrying an umbrella in London. He died four days later.
Prosecutors have failed to identify, charge, or arrest anybody for the crime.
A spokeswoman for the Bulgarian prosecutor's office said the investigation was to be closed on September 11, when the 35-year statute of limitations for prosecuting such crimes expires.
A journalistic investigation into communist-era secret-police files has identified Markov's suspected killer as a secret-police agent and revealed close links between the Bulgarian secret police and the Soviet KGB over the murder.
Based on reporting by Reuters, AFP, and Novinite.com