Former Chechen president Zelimkhan Yandarbiyev was killed in a car blast in Qatar on Friday, the Arab TV station al-Jazeera said.
Two of his bodyguards were reportedly killed and his teenage son, Daud, was said to be serious.
Yandarbiyev was on a UN list of groups and people with suspected links to the Al Qaeda.
The acting Chechen president in 1996, he headed the rebel delegation that held talks with Russian president Boris Yeltsin and prime minister Viktor Chernomyrdin in the same year.
The Chechen leader, who was on Interpol's wanted list since 2001, was living in Qatar for three years.