The footage included a shot of an open laptop with a list of openings allegedly researched by Caruana along with the names of three grandmasters - Leinier Domínguez, Alejandro Ramírez and Ioan-Cristian Chirila - who could potentially be working as seconds in the American's camp, The Guardian reported.

Caruana was polite but non-committal during the post-match press conference on the question of whether it was an accidental blunder or a piece of deliberate misinformation.

Carlsen appeared more relaxed.

"Well, I’ll have a look at the video and then make up my mind," he said with a smile, prompting laughter from the press gallery.

This was their shortest match so far, involving 34 moves and over in three hours to bring the score to 2-2.

Carlsen, playing with the white pieces, offered a surprise to onlookers with the English Opening, which he had played only once in 37 meetings with his American rival, a year younger than him at 26.

Caruana, however, resisted the initiative.

"He seems to have out-prepared me with the black pieces so far so I’ll have to try harder," the champion said.

Both players will have a rest day tomorrow before the best-of-12-games match organised by the World Chess Federation (FIDE) resumes with Caruana playing as white in Game 5 on Thursday (November 15).

At the FIDE Women’s World Chess Championships in Khanty-Mansiysk, defending champion Ju Wenjun of China reached the semi-finals after seeing off the awkward challenge of the 19-year-old surprise package of the tournament, Guirukhbegim Tokhirjonova.

The 40th-ranked Uzebkistan player, who had previously beaten China’s Tan Zhongyi, whom Jun beat for the title in May, had drawn the first of their two scheduled quarter-finals but was beaten today by her 27-year-old opponent, who thus progressed by a score of 1½-½.

Ju will await the winner of the quarter-final between the fourth and fifth seeds, respectively Anna Muzychuk of Ukraine and Alexandra Koteniuk, who have each won a match and will now go to a tiebreaker.

The same situation holds for the quarter-final between Muzychuk’s younger sister Mariya, world champion between 2015 and 2017, and her Kazakhstan opponent Zhansaya Abdumalik.

Adbumalik, world ranked 15, had gone 1-0 ahead, but the Ukrainian, ranked seven, levelled the match today.

The winner is scheduled to meet the highest ranked player remaining other than Jun, Russia’s third-ranked Kateryna Lagno, who completed a 2-0 win over China’s Lei tingjie.