(CNN) - The mother of Amir Hekmati, an American sentenced to death in Iran for espionage, visited her son last month, sources close to the family said.
Behnaz Hekmati traveled to Iran alone at the end of January and was able to see her son. She has since returned back to Flint, Michigan.
Hekmati, who served in the U.S. Marines from 2001 to 2005, was arrested in August while visiting his grandmother and other relatives in Iran. His family has said he made the trip after obtaining permission from the Iranian Interests Section of the Pakistani Embassy in Washington.
Iran's semiofficial Fars news agency has reported that he was convicted of espionage, "working for an enemy country," being a member of the CIA and "efforts to accuse Iran of involvement in terrorism."
In January, Hekmati's lawyer said the ex-Marine's case should be judged on humanitarian, not political grounds. Pierre Prosper said he was at risk of falling victim to the animosity between the United States and Iran.
"What worries me most is that this case is entrapped in an intense political environment," the U.S.-based lawyer said.