(CNN) -- American Amir Mirzaei Hekmati, on trial in Iran for espionage, has been sentenced to death nearly five months after he was arrested, Iran's semi-official Fars news agency reported Monday.
A court convicted Hekmati of "working for an enemy country ... for membership in the CIA and also for his efforts to accuse Iran of involvement in terrorism," according to Fars.
Ahead of the verdict, his family and the United States denied the accusations against him.
"We are deeply concerned that Amir is not receiving a fair trial and has not been afforded due process," a family statement released last week said. "We have struggled to provide Amir with an attorney in Iran. We have sought to hire at least 10 different attorneys in Tehran to no avail."
The family said their son was being represented by a government-appointment lawyer.
"Under any standard, this is not acceptable due process of law," the statement said. " We will not stop hoping and praying for justice, for peaceful dialogue with Iran, and for Amir's safe return home."
Hekmati, a former U.S. Marine, was arrested in August while visiting his grandmother and other relatives, his family in Michigan said last month.
The Hekmatis said their son served in the Marines from 2001 to 2005. Later, he started his own linguistics company and contracted his services to the military as well as civilian businesses.
His military contracts included cultural competency training. He worked with troops at military bases to promote understanding of, and positive communication, with people of other cultures, his family said.
Fars reported that Hekmati said he worked for the U.S. Army for four years and later the CIA, where he was sent to Afghanistan and had access to secret documents.
Hekmati was supposed to give his information to the Iranians in two parts -- the first part for free, and if they liked it he would ask for $500,000 for the second part, the news agency said.
Hekmati said he was to get a receipt from the intelligence ministry for the money, Fars reported. The judge speculated whether the receipt would later be used as evidence linking Iran to terrorist activities, the news agency said.
If Iran had paid, Hekmati told the judge, he would have kept the money and lived in Iran, according to Fars.
CNN's Azadeh Ansari and Shirzad Bozorgmehr contributed to this report.