SEMPORNA: A 37-year-old Chinese tourist is believed to have drowned while diving in the waters off Sipadan Island here yesterday.

District police chief Superintendent Mohd Sabri Zainol said they were alerted to the incident after a report was lodged at 6.45pm.

"The complainant, a diving instructor, along with four other dive guides, had brought eight divers from various countries to Sipadan Island for a diving activity.

"At around 10.45am, the male Chinese tourist entered the sea without the instructor's permission and immediately sank," he said in a statement.