Gujarat's Bharatiya Janata Party (BJP) legislator Fatehsinh Chauhan was arrested for his alleged involvement in the 2002 riots in the state's Rajgarh town.
The arrest was ordered by the Supreme Court appointed Special Investigation Team (SIT). The legislator from Rajgarh was evading arrest for a long time, police said.
Chauhan would be presented before a local court in Ahmedabad later in the evening.
More than 1,000 people, mostly Muslims, were killed in the riots that followed the burning of the S-6 sleeper coach of Sabarmati Express at the Godhra station on July 27, 2002, in which 59 passengers were burnt to death.
The legislator has also been reprimanded by the Election Commission for his remarks against Congress chief Sonia Gandhi in Rajgarh during the recently concluded Lok Sabha elections.