March 17 (UPI) -- U.S. Secretary of State Marco Rubio has designated a Jewish Iranian-American imprisoned for nearly a year in Iran as wrongfully detained, according to his family.

Kamran Hekmati, a jeweler and longtime resident of Great Neck, N.Y., was detained by Iranian authorities at Tehran's Imam Khomeini International Airport on May 17, according to the Bring Kamran Home website.

He was in the country for a family matter, and was detained while attempting to return to the United States. The website states he was formally arrested on July 28, less than two weeks after the United States bombed Iran's nuclear facilities.

His family told UPI in a statement that they were notified on Monday of Rubio's designation, an official recognition that the United States believes Hekmati is being held in Iran on false charges.

"We are so grateful to President [Donald] Trump and Secretary Rubio for their designation of Kamran Hekmati as a wrongful detainee," Shohreh Nowfar, Hekmati's cousin, said in a statement provided to UPI by Global Reach, a U.S. nonprofit that advocates for Americans imprisoned abroad.