A well-known Azerbaijani writer and journalist has died in a prison hospital, RFE/RL's Azerbaijani Service reports.
Novruzali Mammadov, 68, was a leading activist of the Talysh minority of Azerbaijan, who speak a language related to Persian.
He was the head of the Talysh Cultural Center in Baku and editor of the newspaper "Tolishi sado" (The Voice of Talysh).
Azerbaijani human rights activist Elchin Bekhbudov told RFE/RL that prison officials told him that Mammadov's health deteriorated abruptly on August 17 and he died.
He was found guilty last year of spying for Iran and sentenced to 10 years in prison. International and domestic human rights activists had called for Azerbaijani authorities to release Mammadov.
His colleagues and relatives say the charges against him were politically motivated and he was considered by activists to be a political prisoner.
Lydia Arroyo, Amnesty International's press officer for Europe and Eurasia, told RFE/RL that her organization has "always been concerned about the allegations of ill-treatment" against Mammadov.
Arroyo said Mammadov's trial was "apparently unfair" and simply because of his "promotion of the Talysh culture and language in Azerbaijan."
She added that Amnesty was "concerned about the conditions in which Mammadov was held, not least because of his poor health."
Arroyo called on Azerbaijani officials to investigate his death, but said Amnesty has "serious concerns" that they could conduct an impartial investigation.
Talysh officially make up some 1 percent of Azerbaijan's 8.8 million people, although other estimates put their numbers much higher. There are also some 110,000 Talysh living in Iran.