Eight diners at the Mandarin Oriental have fallen ill after eating raw oysters, salmon sashimi, crab legs and brown crab.
The clusters involved five men and three women, who had dinner at the Clipper Lounge, Mandarin Oriental on January 31 and February 2 respectively.
They developed diarrhoea, abdominal pain, vomiting and fever about 25 to 75 hours after the meal.
Four sought medical advice but did not require hospitalisation.
The authorities conducted an investigation and collected food and environmental samples for testing.