Officials at the tournament became suspicious when Arcangelo Ricciardi, who is ranked 51,366 in the world, began beating far better players.

Mr Ricciardi was reportedly blinking in an unusual manner and holding his hand under his armpit.

Confronted by referee Jean Coqueraut, he refused to open his shirt.

Officials believe the 37-year-old was using the camera, hung around his neck, to transmit the game to someone with a chess computer program, who was feeding back moves using Morse code.

Mr Coqueraut said he began to suspect something was wrong early on in the competition.

"In chess, performances like that are impossible," he told La Stampa newspaper.

He said Mr Ricciardi did not get up at all during hours of playing and kept his thumb tucked in his armpit.

The 37-year-old player was also "batting his eyelids in the most unnatural way", Mr Coqueraut said.

"Then I understood it," he said. "He was deciphering signals in Morse code."

When Mr Ricciardi refused to open his shirt, officials asked him to pass through a metal detector which picked up a pendant hanging underneath his shirt.

The pendant contained a tiny video camera connected to a small box under his armpit, officials said.

The incident follows a high-profile cheating case in Moscow in April, where a chess grandmaster was expelled after he was discovered using a smartphone in the toilet to check his moves.

Gaioz Nigalidze aroused suspicions when he repeatedly used the same toilet cubicle each time for 10 minutes or more. When officials checked the stall, they discovered a smartphone wrapped in toilet tissue buried in the bin.

The Imperia Chess Festival is Italy`s longest running open event and attracts some of the biggest names in the sport.

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