Hypnotism in a chess game

[Alexandoy]

In the 1978 world chess championship between champion Victor Korchnoi and challenger Anatoly Karpov there was a claim by the camp of Korchnoi that a certain Dr. Zuchar in the audience is a hypnotist that is affecting the game of Korchnoi. There was no proof to the allegation but maybe the results of the championship games is proof because Karpov won handily over the champion.

 

[nangk08]

I never heard about this incident! Can it be true? and were any investigations carried out into this claim ? One thing that does strike discord is that, to hypnotise someone, there should be eye contact and if Karpov and Korchnoi were both engrossed in their game, as chess requires lot of focus and concentration, then how could someone in the audience hypnotise the player?