The first senior OGPU officer to defect to the West (1930), he wrote revelatory books, which led to massive arrests of Soviet intelligence assets across the Near East and Central Asia.

In late October 1929, Agabekov left Odessa for Istanbul as an "illegal" rezident in Turkey, where he replaced the Trotskyist Yakov Blumkin (alias Zhivoi), who was soon executed in Moscow.

According to Agabekov, prior to 1930, Turkey was viewed by OGPU as a friendly power because of the Russian-Turkish Treaty of Moscow, but offers of co-operation by the Turkish police and intelligence were declined.

[4] Mikhail Trilisser, the chief of the OGPU Foreign Branch (1922–1930), whose patronage Agabekov enjoyed,[5] envisioned Istanbul as a base of Soviet espionage activity for the entire Near East.

The publication of Agabekov's English-language book OGPU: The Russian Secret Terror in 1931 led to sweeping arrests of hundreds of Soviet agents and sympathisers in Persia as well as other Near Eastern countries and caused a sharp deterioration of Moscow's relations with Rezā Shāh.

However, according to the 1997 memoir attributed to Pavel Sudoplatov,[10] his assassination was perpetrated by a retired Turkish officer in Paris and organised by Aleksandr Mikhaylovich Korotkov (ru), who later became deputy chief of the Foreign Intelligence.