Russian state investigators said Darya Dugina, daughter of idealogue Alexander Dugin, was killed after a suspected explosive device detonated on the Toyota Land Cruiser she was traveling in on Saturday evening.
State news agency TASS quoted Andrei Krasnov, who knew Ms Dugina, as saying the vehicle belonged to her father and he was probably the intended target.
Father and daughter had been attending a festival outside Moscow and Ms Dugin had decided to switch cars at the last minute, Russian government newspaper Rossiiskaya Gazeta reported.
TV footage accompanying the statement showed investigators collecting debris and fragments from the site of the explosion.
They said they would be carrying out forensic examinations to determine what had happened.