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.