Goar Vartanyan, one half of a legendary Soviet spy couple who helped prevent a Nazi assassination of allied leaders in Tehran in 1943, has died at age 93.
Goar, who with her husband Gevork worked as a secret agent on numerous missions abroad, died on Monday, Russia's SVR foreign intelligence service said.
She was to be buried at Moscow's prestigious Troyekurovskoe cemetery, possibly on Friday, SVR spokesman Sergei Ivanov told AFP.
Goar helped thwart Operation Long Jump -- a Nazi plot to assassinate Joseph Stalin, Winston Churchill and Franklin Roosevelt at the first meeting between the "Big Three" in Tehran in 1943.
Born on January 25, 1926 in Gyumri in what was then Soviet Armenia, Goar moved with her family to Iran in the early 1930s.
She joined an anti-fascist group at the age of 16 and eventually worked with Gevork to expose German agents.
When Hitler ordered the plot to kill the "Big Three" at a conference in Tehran, their group reportedly followed Nazi agents and exposed the plan.
The couple moved to the USSR in 1951 and had a long career as secret agents.
The SVR -- one of the successor agencies to the Soviet-era KGB -- said they were involved in "active intelligence work" in "extreme conditions in many countries" but did not provide any details.
Gevork, who was decorated with the Hero of the Soviet Union award, died in 2012 aged 87.
"Gevork used to say that of the five rays of his Hero Star, at least two belonged to his beloved Goar," Ivanov said.
In June 2017, President Vladimir Putin -- himself a former KGB agent -- visited SVR headquarters and praised secret agents including the Vartanyans.
"They are modest people, they don't like to be called heroes," he said.
The couple returned to the USSR in 1986. Goar retired the same year but continued to train young agents.
Former Soviet spy Mikhail Lyubimov told AFP he doubted that Russia would reveal more details of the couple's operations "so as not to cause political scandals in the countries they worked".