Magnus Carlsen and Fabiano Caruana on Tuesday played out the fourth consecutive draw at the World Chess Championships to be tied 2-2. The draw was played out over 34 moves and lasted less than three hours – the shortest so far.

This was before a controversy sprouted on Tuesday morning when a clip was uploaded on YouTube showing Caruana’s preparation for the game, including specific variations he was preparing for London and how he would defend certain moves. The clip was later deleted.

When asked if he had seen the video, Carlsen said, as quoted by, “I can truthfully say that I haven’t seen the video, but I am aware of its existence.” Caruana, meanwhile, declined to comment on the video.

During the game, Carlsen, playing with white pieces, set the pace with an English opening, offering a novelty with 11. b4. However, Caruana hit back with 11. ...Bd6. The world no 1 avoided taking risks despite being vulnerable on queenside. After an exchange of queens and bishops, the duo agreed to a draw after less than three hours.

Wednesday will be a rest day before Caruana and Carlsen continue their battle for world supremacy in the best-of-12-games encounter, which is the first between the top two in the world in 28 years. The American will be playing with white pieces in the fifth round.