Lightning protection of a pitch-controlled wind turbine blade

A wind turbine rotor including a rotor hub ( 3 ) and a plurality of blades ( 4 ), and where each blade root ( 16 ) is connected to said rotor hub through a pitch bearing ( 5 ) in such a manner that the pitch angle of the blade is adjustable by a turning of the blade about its longitudinal axis relative to the rotor hub. The blade is provided with at least one electrically conducting lightening down-conductor ( 6 ) extending in the longitudinal direction of the blade to the blade root and being electrically isolated from the pitch bearing ( 5 ). A spark gap ( 15 ) is provided between the lightning down-conductor and the rotor hub, said spark gap ( 15 ) being adapted to conduct a lightning current passing through the lightning down-conductor. A sliding contact connection ( 7, 12 ) is provided parallel to the spark gap ( 15 ) between the lightning down-conductor ( 6 ) and the rotor hub ( 3 ), said sliding contact connection ensuring electrical contact between said lightening down-conductor ( 6 ) and said rotor hub ( 3 ) irrespective of the pitch angle of the blade. The invention also relates to a wind turbine including such a rotor.