Al-Sabeel named the Tunisian as Fahmi al-Aouni and said he died in clashes in the coastal city of Sousse that left 10 people injured. Clashes also took place in the capital, Tunis.
The riots came a day after the Spring of Arts exhibition in Tunis's upscale La Marsa suburb sparked an outcry from some the puritanical Salafites who say it insulted Islam.
The work that appears to have caused most fury amongst hardliners spelt out the name of God using insects.
Police imposed a curfew late Tuesday after thousands of Salafites rampaged in through parts of Tunis, hurling rocks and petrol bombs at police stations, a court house and the offices of secular parties.
The interior ministry said a total of 62 people were detained and 65 members of the security forces were wounded trying to quell the riots, the worst clashes since last year's revolt ousted autocratic president Zine al-Abidine Ben Ali and triggered uprisings across the Arab world.