Gaioz Nigalidze could face a three-year ban if the complaint against him is upheld.
The reigning Georgian national champion was playing Armenian Tigran Petrosian in the sixth round at the Dubai Open.
Petrosian alerted officials after noticing that his opponent was visiting the bathroom at regular intervals.
Nigalidze was apparently using the same cubicle each time for ten minutes or more, arousing his rival's suspicions.
When the player emerged from the toilet, officials discovered a smartphone wrapped in toilet tissue and hidden in the cubicle.
"He denied it was his, but it was logged into his Facebook page and there was a chess program running on it, showing his positions," the tournament director Yahya Mohamed Saleh told the BBC from Dubai.
The first prize up for grabs at the competition was $12,000 (£8,000).
'Very talented'
Gaioz Nigalidze did not respond to an email request for comment.
The Georgian Chess Federation called the incident "very bad," but said it was waiting to hear the player's side of the story before passing judgement.
"He is very talented," Sofiya Nikoladze told the BBC.
人生的枷鎖愈是繁重
会社の名刺で仕事を
occupation waste at many sites."
好好愛丈夫，做一個好妻子。
はたと気が付
ても八百屋の店先から消
我希望人們更誠實一步
勾畫出一幅美麗的風景
我們不必總是風塵僕僕
短短三個小時的車
に記帳と帳簿書