Dimitri A. Khalezov is a former commissioned officer of the so-called “military unit 46179”, otherwise known as “the Special Control Service” of the 12th Chief Directorate of the Defense Ministry of the USSR.
The Special Control Service, also known as the Soviet atomic (later “nuclear”) intelligence was a secret military unit responsible for the detection of nuclear explosions (including underground nuclear tests) of various adversaries of the former USSR and was responsible for controlling observance of various international treaties related to nuclear testing and to peaceful nuclear explosions.
After 11 September 2001 Khalezov undertook extensive research on the collapse of the three World Trade Centre Towers. The research is claimed to demonstrate, beyond reasonable doubt, that the three WTC towers were demolished by three underground thermo-nuclear explosions, making the the subsequent "Ground-Zero" name for the site accurate in the traditional and accepted meaning of the term.
Moreover, Khalezov claims that he knew about the in-built so-called “emergency nuclear demolitions scheme” for the Twin Towers as long ago as the 1980's, whilst a serviceman in the Soviet Special Control Service.
The complete interview: