The suspect was captured in a special operation conducted by American military near the city of tall afar in Northern Iraq. It was conducted last month, however, to date information was not disclosed.
The source Agency the associated press claim that the special forces captured a man worked on a program to build chemical and biological weapons during the reign of Saddam Hussein, and now works for the militants.
U.S. authorities confirm capture of high-ranking militants of the IG, but refuse to provide any details about his identity.
On Wednesday the U.S. aircraft launched several airstrikes against targets in Iraq, Islamists allegedly engaged in developing chemical weapons.
Also on Wednesday there were unconfirmed reports about the use of militants to chemical weapons during the shelling of villages in Northern Iraq. As a result 40 people from the village began to have difficulty breathing, but the victims were not.
Extremist group "Islamic state" operates mainly on the territory of Syria and Iraq. Declared a terrorist organization and banned in many countries, including Russia and the UK.