Bechir Gholli, a Tunisian detained in connection with an attack on the US embassy in Tunis in September, has died after going without food for nearly two months ago, his lawyer says.
Another detained suspect on hunger strike, Mohamed Bakhti, 28, was in a "critical condition", the lawyer said on Thursday.
"Bechir Gholli, on hunger strike for 57 days, was transferred to hospital on November 13 and died today from a heart attack," Abdelbasset Ben Mbarek told AFP by telephone on Thursday.
Gholli, 23, the father of a six-month-old baby, was accused of participating in deadly disturbances outside the US embassy in September, which the authorities said were orchestrated by Salafist hardliners.
"He was innocent, he went on hunger strike to defend himself," Ben Mbarek said, adding that his client was not a Salafist.
The justice ministry declined to comment but a judicial source confirmed that two hunger-strikers had been taken to hospital in critical condition on Thursday.
Several hundred protesters, angry over an anti-Islam film made in the US, stormed the sprawling US embassy compound in a suburb of the capital on September 14, in violence that left four people dead and dozens wounded.
More than 100 people were detained following the attack. Tunisia's hardline Islamists have carried out numerous acts of violence since last year's revolution that ousted veteran strongman Zine El Abidine Ben Ali.