In a case that is raising the already high tensions between the United States and Iran, an Iranian court has convicted the son of a professor at Mott Community College of working for the CIA and sentenced him to death.

According to the Detroit Free Press, state radio reported the conviction today. Iran charges that as a former U.S. Marine, Amir Mirzaei Hekmati received special training and served at U.S. military bases in Iraq and Afghanistan before heading to Iran for his alleged intelligence mission. The radio report did not say when the verdict was issued. Under Iranian law, he has 20 days to appeal.

The 28-year-old former military translator was born in Arizona and graduated from high school in Michigan. His family is of Iranian origin. His father, a professor at a community college in Flint, Michigan, has said his son is not a CIA spy and was visiting his grandmothers in Iran when he was arrested.

Hekmati's trial took place as the U.S. announced new, tougher sanctions against Iran over its nuclear program, which Washington believes Tehran is using to develop a possible atomic weapons capability.

The court convicted him of working with a hostile country, belonging to the CIA and trying to accuse Iran of involvement in terrorism, today's report said.

The U.S. State Department has demanded Hekmati's release.