Bulgaria said on Wednesday it was closing its investigation into one of the most notorious assassinations of the late Cold War, the killing of exiled dissident Georgy Markov with the poisoned tip of an umbrella on London's Waterloo Bridge.
Markov, a writer, journalist and opponent of Bulgaria's then communist regime, died on September 11, 1978 after a stranger shot a poisoned pellet into his leg. Prosecutors have failed to identify, arrest or charge anybody for the crime, known as the "Bulgarian umbrella".
"The probe will be abandoned as of tomorrow, when the absolute statute of limitations of 35 years will expire," the prosecutors' office spokeswoman Rumiana Arnaudova said.
"To overcome the statute of limitations, we need to have a suspect for the crime arrested, charged or put on a search list. As of the moment, we have not established the perpetrator and neither of the above actions are undertaken," Arnaudova said.
British police have their own investigation of the affair.
According to accounts of the incident, Markov, who defected to the West in 1969, was waiting for a bus when he felt a sharp sting in his thigh. A stranger fumbled behind him with an umbrella he had dropped and mumbled "sorry" before walking away.
Markov died four days later of what is believed to be ricin poisoning, for which there is no antidote.
Five years ago, the Bulgarian daily Dnevnik published an investigation into communist-era secret police files which identified Markov's suspected assassin as an agent code-named "Piccadilly" .
The files show how the agent had "special training" from Bulgaria's secret police and received two medals, several free holidays and $30,000 after Markov's death, Dnevnik said, adding that Markov's case was discussed with the KGB in Moscow.
In 2008, Bulgarian prosecutors extended the investigation by 5 years, hoping that access to communist era secret police files would help solve the case. But Bulgarian authorities say this brought no clarity about the identity of the killer.