Moscow ? Garry Kasparov, a chess superstar locked in the political match of his life with President Vladimir Putin, was called in for four hours of questioning by Russian security agents Friday and ordered to see prosecutors today.

The 44-year-old grandmaster’s aggressive style on the chessboard and his refusal to settle for a draw earned him a series of world championships. But he’s aware that a blunder in this struggle could cost him dearly.

An aide, Marina Litvinovich, later said the summons might be prosecutors’ reaction to a request by lawmakers for an investigation into Kasparov’s detention at an anti-Putin rally in Moscow a week ago – not a prelude to his arrest. Kasparov, though, sounded concerned after hearing he had been summoned by prosecutors.

Kasparov was among the chief organizers of last weekend’s Dissenters’ Marches, at which participants were charged and beaten by truncheon-wielding riot police. He was arrested at the Moscow protest and held for hours while his supporters demanded his release.