Benjamin Briere, a French national held in Iran, has gone on hunger strike for the second time since his incarceration in May 2020, his sister and his lawyer said on February 6.
Briere was sentenced to eight years in jail for espionage after flying a drone near the Iran-Turkmenistan border.
He is one of seven French and more than two dozen foreign nationals who campaigners say Iran has jailed in a strategy of hostage-taking to extract concessions from the West.
A hunger strike is the "only weapon he has," his sister, Blandine Briere, said in a statement. He stopped eating on January 28, she explained.
France's foreign ministry called his conviction "unacceptable" and said it had "no basis in fact".
Mr Brière's family have insisted he is innocent and say he is being used as a political pawn.