The project was initiated at the end of the Iran-Iraq war in 1989. The plan involves dozens of immense tunnels and facilities built under the mountains near Tehran.
"North Korean experts have cooperated with the Tehran regime in the design and building of this complex," said Alireza Jafarzadeh, president of Strategic Policy Consulting, and a former representative of the Mujahedeen-e-Khalq.
"Many blueprints of the site have been prepared by North Korean experts."
Hemmat Industries Group Factory, the most important branch of Iran's Aerospace Industries Group is currently building Shahab-1, Shahab-2, Shahab-3 and Ghadar missiles, according to Jafarzadeh. Shahab-3 and Ghadar missiles have nuclear warhead capability.
"Shahab-3 missiles are being manufactured in large numbers, and are already part of the Iranian Revolutionary Guards arsenal," Jafarzadeh told United Press International.
The Ghadar missile is still in the production stage, and is 70 percent complete.
Shahab-3 has a range of 1,300 to 1,900 km (800-1,100 miles) and Ghadar has a range of 2,500 to 3,000 km (1,150-1,850 miles).
Working in utmost secrecy Hemmat Industries Group have been allocated code numbers. Movahed Industries, codenamed 7,500, builds the body of the missile and does final assembly. Karimi Industries, the most secretive part of the program, codenamed 2500, builds the warhead.
This group is located in the largest tunnel at the Khojir complex deep inside the Khojir and Bar Jamali Mountain. The tunnel is about 1,000 meters (yards) long, 12 meters wide.
Iran has refused to allow U.N. inspectors to visit the military sites where much of the nuclear weapons work is reported to be conducted.
Information obtained by Jafarzadeh from source in Iran indicate that A.Q. Khan traveled to Iran in 1987 where he met with three top commanders of the Iranian Revolutionary Guards who were working at the time on nuclear research. The IRGC delegation was headed by Brig. Gen. Mohammad Eslami.