Federal prosecutors in New York have charged three Iranians with illegally exporting "many tons" of carbon fiber, a controlled material with military and nuclear uses, to Iran.

Geoffrey S. Berman, U.S. attorney for the Southern District of New York, announced the charges Tuesday following the successful extradition of one of the three, Behzad Pourghannad, from Germany on Monday.

The other two defendants, Ali Reza Shokri and Farzin Faridmanesh, remain at large, according to federal authorities.

Carbon fiber is critical to two technologies related to nuclear proliferation. It is used in the fabrication of nose cones for long-range missiles and the manufacture of the rotors in the centrifuges that enrich uranium. Iran is prohibited from acquiring carbon fiber under the provisions of U.S. sanctions against the nation.

According to the indictment unsealed in White Plains federal court, the three defendants, operating out of Iran, acquired "many tons" of carbon fiber between 2008 and 2013 from an unidentified U.S. broker and shipped it to Iran through third countries. The material was falsely described as "acrylic" in export documents, authorities said.

The indictment does not specify how much carbon fiber made it to Iran, but stated that In late 2007 and early 2008, Shokri and a Turkey-based co-conspirator "successfully arranged" for the illegal export and transshipment of carbon fiber from the U.S. through Europe and the United Arab Emirates to Iran.

Shokri is charged with the procurement of carbon fiber. Pourghannad is accused of financing the transactions, and Faridmanesh is charged with the transshipment.

In a statement, Berman said, "Carbon fiber has many aerospace and defense applications, and is strictly controlled to ensure that it doesn't fall into the wrong hands. Pourghannad and his co-defendants allegedly went to great lengths to circumvent these controls and the United States' export laws. Together with our law enforcement partners, we will continue to protect our nation's assets and protect our national security."

"Iran remains determined to acquire U.S. technology with military applications, and the FBI is just as determined to stop such illegal activity," added Assistant FBI Director John Brown, who is with the bureau's counterintelligence division.

Pourghannad was arrested May 3, 2017, in Germany and extradited to the U.S., arriving Monday. He made his first court appearance Tuesday in White Plains federal court before U.S. Magistrate Judge Judith C. McCarthy.