The founder of the Islamic State group's news agency was killed with his daughter in an air strike last week in eastern Syria, his brother and Syrian opposition activists said on June 1.
The militant group itself has not reported the death of the Amaq agency founder, Baraa Kadek, also known as Rayan Meshaal.
Activists said Meshaal was close to the IS leadership, gaining their trust and reportedly meeting with the enigmatic leader Abu Bakr al-Baghdadi.
Meshaal's brother, Hozaifa, and former friends reported his death on Facebook, saying he died when an air strike by the U.S.-led international coalition fighting IS hit his home in the town of Mayadeen in Deir el-Zour province.
A former colleague said Meshaal and his daughter and wife were wounded in an air strike on May 26 and that he died of his wounds on May 31, AP reported.
Mohammed Khaled, executive manager of Aleppo 24, an activist-operated media platform and a former friend of Meshaal, told AP his wife remains in critical condition.
The Amaq news site, founded in 2014, is considered the mouthpiece of IS and has been used to claim responsibility for at least two dozen attacks around the world.