The United States has confirmed the death of an Egyptian-American, Moustafa Kassem, who had been imprisoned for alleged involvement in anti-government protests after President Abdul Fattah al-Sisi came to power in Egypt in 2013.
The US State Department said Mr Kassem's death in custody was needless, tragic and avoidable.
He had been on a hunger strike and had stopped taking liquids on Thursday.
He was one of 600 people sentenced in a mass trial over a sit-in that ended with the security forces killing hundreds of protesters.
The New York Times says the 54-year-old had insisted he had no links to opposition politics and when he was detained by Egyptian soldiers, they "snatched his American passport and stomped it on the ground".
An American imprisoned in Egypt for 6 years on what he insisted were false charges, and whose case was championed by Vice President Mike Pence, died after a long hunger strike, the State Department said https://t.co/4V7v34a5R8
— The New York Times (@nytimes) January 14, 2020