The family of a former U.S. Marine imprisoned in Iran says he is going on a hunger strike.
Sarah Hekmati said in an e-mail to the Associated Press that her brother, Amir, told the family by phone on December 16 about the hunger strike.
Hekmati, a dual U.S.-Iranian citizen, was arrested in 2011 and sentenced to 10 years in prison for collaborating with the U.S. government. He says he is innocent.
Sarah also said her brother had dictated a letter asking U.S. President Barack Obama not to forget him as dialogue continues between Washington and Tehran over Iran's nuclear program.
The letter called on Obama to "make it clear" that his "case is unrelated and should be resolved independent" of those talks.
The U.S. government has asked Iran to free Hekmati, whose family lives in Michigan.