The 36-year-old Selahattin Demirtas, a lawyer by profession who worked for the Turkish Human Rights Association for several years, won 288 of 289 votes cast to become leader of the Peace and Democracy Party (BDP), the report said.

Gultan Kisanak was elected as his de facto number two.

The BDP was relatively unheard of until the Constitutional Court banned its much larger ally, the Democratic Society Party (DTP), in December for links to separatist Kurdish rebels.

The DTP's 19 lawmakers, among them Demirtas and Kisanak, then joined the BDP rather than sit as independents in parliament.

The court ruling, which sparked violent street protests, delivered a serious blow to a government plan to expand Kurdish freedoms in return for ending a deadly 25-year insurgency by the outlawed Kurdistan Workers' Party for self-rule in the mainly Kurdish southeast.